From 38becacacee43b40d02e33c97f0dc3bda83f42e6 Mon Sep 17 00:00:00 2001
From: Todd Gamblin <tgamblin@llnl.gov>
Date: Mon, 18 Feb 2013 23:46:04 -0800
Subject: [PATCH] Dependencies now work.  Added libelf, libdwarf.

---
 bin/spack                                  |   2 +-
 lib/spack/env/c++                          |   1 +
 lib/spack/env/c89                          |   1 +
 lib/spack/env/c99                          |   1 +
 lib/spack/env/case-insensitive/CC          |   1 +
 lib/spack/env/cc                           |  69 +++++
 lib/spack/env/clang                        |   1 +
 lib/spack/env/clang++                      |   1 +
 lib/spack/env/cpp                          |   1 +
 lib/spack/env/g++                          |   1 +
 lib/spack/env/gcc                          |   1 +
 lib/spack/env/ld                           |   1 +
 lib/spack/spack/Package.py                 | 309 ++++++++++++++++-----
 lib/spack/spack/__init__.py                |   3 +-
 lib/spack/spack/arch.py                    |  34 +++
 lib/spack/spack/attr.py                    |   6 +
 lib/spack/spack/cmd/__init__.py            |  12 +-
 lib/spack/spack/cmd/arch.py                |  12 -
 lib/spack/spack/cmd/clean.py               |  27 +-
 lib/spack/spack/cmd/create.py              |  77 +++--
 lib/spack/spack/cmd/edit.py                |  24 +-
 lib/spack/spack/cmd/fetch.py               |   3 +-
 lib/spack/spack/cmd/graph.py               |   6 +
 lib/spack/spack/cmd/install.py             |  15 +-
 lib/spack/spack/cmd/list.py                |  22 ++
 lib/spack/spack/cmd/stage.py               |   3 +-
 lib/spack/spack/cmd/uninstall.py           |  19 +-
 lib/spack/spack/colify.py                  | 159 +++++++++++
 lib/spack/spack/compilation.py             |  52 ++++
 lib/spack/spack/exception.py               |  23 ++
 lib/spack/spack/globals.py                 |  15 +-
 lib/spack/spack/packages/__init__.py       | 137 ++++++++-
 lib/spack/spack/packages/libdwarf.py       |  41 +++
 lib/spack/spack/packages/libelf.py         |  13 +
 lib/spack/spack/stage.py                   |  66 ++++-
 lib/spack/spack/test/test_versions.py      | 103 +++----
 lib/spack/spack/tty.py                     |   9 +-
 lib/spack/spack/{fileutils.py => utils.py} | 106 ++++++-
 lib/spack/spack/validate.py                |   2 +-
 lib/spack/spack/version.py                 |  44 ++-
 40 files changed, 1163 insertions(+), 260 deletions(-)
 create mode 120000 lib/spack/env/c++
 create mode 120000 lib/spack/env/c89
 create mode 120000 lib/spack/env/c99
 create mode 120000 lib/spack/env/case-insensitive/CC
 create mode 100755 lib/spack/env/cc
 create mode 120000 lib/spack/env/clang
 create mode 120000 lib/spack/env/clang++
 create mode 120000 lib/spack/env/cpp
 create mode 120000 lib/spack/env/g++
 create mode 120000 lib/spack/env/gcc
 create mode 120000 lib/spack/env/ld
 create mode 100644 lib/spack/spack/arch.py
 delete mode 100644 lib/spack/spack/cmd/arch.py
 create mode 100644 lib/spack/spack/cmd/graph.py
 create mode 100644 lib/spack/spack/cmd/list.py
 create mode 100644 lib/spack/spack/colify.py
 create mode 100644 lib/spack/spack/compilation.py
 create mode 100644 lib/spack/spack/exception.py
 create mode 100644 lib/spack/spack/packages/libdwarf.py
 create mode 100644 lib/spack/spack/packages/libelf.py
 rename lib/spack/spack/{fileutils.py => utils.py} (54%)

diff --git a/bin/spack b/bin/spack
index 1fd47d5e8c..081c76ca21 100755
--- a/bin/spack
+++ b/bin/spack
@@ -19,7 +19,7 @@ import spack
 # Command parsing
 parser = argparse.ArgumentParser(
     description='Spack: the Supercomputing PACKage Manager.')
-parser.add_argument('-V', '--version', action='version', version="%s" % spack.version)
+parser.add_argument('-V', '--version', action='version', version="%s" % spack.spack_version)
 parser.add_argument('-v', '--verbose', action='store_true', dest='verbose')
 
 # each command module implements a parser() function, to which we pass its
diff --git a/lib/spack/env/c++ b/lib/spack/env/c++
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/c++
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/c89 b/lib/spack/env/c89
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/c89
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/c99 b/lib/spack/env/c99
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/c99
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/case-insensitive/CC b/lib/spack/env/case-insensitive/CC
new file mode 120000
index 0000000000..82c2b8e90a
--- /dev/null
+++ b/lib/spack/env/case-insensitive/CC
@@ -0,0 +1 @@
+../cc
\ No newline at end of file
diff --git a/lib/spack/env/cc b/lib/spack/env/cc
new file mode 100755
index 0000000000..f1ace0d3f7
--- /dev/null
+++ b/lib/spack/env/cc
@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+import sys
+import os
+import subprocess
+import argparse
+
+def get_path(name):
+    path = os.environ.get(name, "")
+    return path.split(":")
+
+# Import spack parameters through the build environment.
+spack_lib      = os.environ.get("SPACK_LIB")
+spack_deps     = get_path("SPACK_DEPENDENCIES")
+spack_env_path = get_path("SPACK_ENV_PATH")
+if not spack_lib or spack_deps == None:
+    print "%s must be run from spack." % os.path.abspath(sys.argv[0])
+    sys.exit(1)
+
+# Figure out what type of operation we're doing
+command = os.path.basename(sys.argv[0])
+
+# Grab a minimal set of spack packages
+sys.path.append(spack_lib)
+from spack.utils import *
+from spack.compilation import parse_rpaths
+import spack.tty as tty
+
+parser = argparse.ArgumentParser(add_help=False)
+parser.add_argument("-I", action='append', default=[], dest='include_path')
+parser.add_argument("-L", action='append', default=[], dest='lib_path')
+parser.add_argument("-l", action='append', default=[], dest='libs')
+
+options, other_args = parser.parse_known_args()
+rpaths, other_args = parse_rpaths(other_args)
+
+if rpaths:
+    tty.warn("Spack stripping non-spack rpaths: ", *rpaths)
+
+# Find the actual command the build is trying to run by removing
+# Spack's env paths from the path.  We use this later for which()
+script_dir = os.path.dirname(os.path.expanduser(__file__))
+clean_path = get_path("PATH")
+remove_items(clean_path, '.')
+for path in spack_env_path:
+    remove_items(clean_path, path)
+
+# Add dependence's paths to our compiler flags.
+def append_if_dir(path_list, prefix, *dirs):
+    full_path = os.path.join(prefix, *dirs)
+    if os.path.isdir(full_path):
+        path_list.append(full_path)
+
+for prefix in spack_deps:
+    append_if_dir(options.include_path, prefix, "include")
+    append_if_dir(options.lib_path, prefix, "lib")
+    append_if_dir(options.lib_path, prefix, "lib64")
+
+# Add our modified arguments to it.
+cmd = which(command, path=clean_path)
+arguments  = ['-I%s' % path for path in options.include_path]
+arguments += other_args
+arguments += ['-L%s' % path for path in options.lib_path]
+arguments += ['-l%s' % path for path in options.libs]
+
+# Unset some pesky environment variables
+pop_keys(os.environ, "LD_LIBRARY_PATH", "LD_RUN_PATH", "DYLD_LIBRARY_PATH")
+
+rcode = cmd(*arguments, fail_on_error=False)
+sys.exit(rcode)
diff --git a/lib/spack/env/clang b/lib/spack/env/clang
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/clang
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/clang++ b/lib/spack/env/clang++
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/clang++
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/cpp b/lib/spack/env/cpp
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/cpp
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/g++ b/lib/spack/env/g++
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/g++
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/gcc b/lib/spack/env/gcc
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/gcc
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/env/ld b/lib/spack/env/ld
new file mode 120000
index 0000000000..2652f5f42c
--- /dev/null
+++ b/lib/spack/env/ld
@@ -0,0 +1 @@
+cc
\ No newline at end of file
diff --git a/lib/spack/spack/Package.py b/lib/spack/spack/Package.py
index 3fdbbe16f8..57cefb21a9 100644
--- a/lib/spack/spack/Package.py
+++ b/lib/spack/spack/Package.py
@@ -2,16 +2,39 @@
 import os
 import re
 import subprocess
+import platform
+import shutil
 
 from spack import *
+import packages
 import tty
 import attr
 import validate
 import version
-import shutil
-import platform
+import arch
 from stage import Stage
 
+
+DEPENDS_ON = "depends_on"
+
+class Dependency(object):
+    """Represents a dependency from one package to another."""
+    def __init__(self, name, **kwargs):
+        self.name = name
+        for key in kwargs:
+            setattr(self, key, kwargs[key])
+
+    @property
+    def package(self):
+        return packages.get(self.name)
+
+    def __repr__(self):
+        return "<dep: %s>" % self.name
+
+    def __str__(self):
+        return self.__repr__()
+
+
 def depends_on(*args, **kwargs):
     """Adds a depends_on local variable in the locals of
        the calling class, based on args.
@@ -21,40 +44,170 @@ def depends_on(*args, **kwargs):
         locals = stack[1][0].f_locals
     finally:
         del stack
-    print locals
 
-    locals["depends_on"] = kwargs
+        dependencies = locals.setdefault("dependencies", [])
+    for name in args:
+        dependencies.append(Dependency(name))
 
 
 class Package(object):
-    def __init__(self):
+    def __init__(self, arch=arch.sys_type()):
         attr.required(self, 'homepage')
         attr.required(self, 'url')
         attr.required(self, 'md5')
+        attr.setdefault(self, "dependencies", [])
 
-        # Name of package is just the classname lowercased
-        self.name = self.__class__.__name__.lower()
+        # Architecture for this package.
+        self.arch = arch
+
+        # Name of package is the name of its module (the file that contains it)
+        self.name = inspect.getmodulename(self.module.__file__)
 
         # Make sure URL is an allowed type
         validate.url(self.url)
 
-        v = version.parse(self.url)
-        if not v:
+        # Set up version
+        attr.setdefault(self, 'version', version.parse_version(self.url))
+        if not self.version:
             tty.die("Couldn't extract version from '%s'. " +
                     "You must specify it explicitly for this URL." % self.url)
-        self.version = v
+
+        # This adds a bunch of convenient commands to the package's module scope.
+        self.add_commands_to_module()
+
+        # Controls whether install and uninstall check deps before acting.
+        self.ignore_dependencies = False
+
+        # Empty at first; only compute dependents if necessary
+        self._dependents = None
+
+
+
+    def add_commands_to_module(self):
+        """Populate the module scope of install() with some useful functions.
+           This makes things easier for package writers.
+        """
+        self.module.make  = make_make()
+
+        # Find the configure script in the archive path
+        # Don't use which for this; we want to find it in the current dir.
+        self.module.configure = Executable('./configure')
+        self.module.cmake = which("cmake")
+
+        # standard CMake arguments
+        self.module.std_cmake_args = [
+            '-DCMAKE_INSTALL_PREFIX=%s' % self.prefix,
+            '-DCMAKE_BUILD_TYPE=None']
+        if platform.mac_ver()[0]:
+            self.module.std_cmake_args.append('-DCMAKE_FIND_FRAMEWORK=LAST')
+
+        # Emulate some shell commands for convenience
+        self.module.cd         = os.chdir
+        self.module.mkdir      = os.mkdir
+        self.module.makedirs   = os.makedirs
+        self.module.removedirs = os.removedirs
+
+        self.module.mkdirp     = mkdirp
+        self.module.install    = install
+        self.module.rmtree     = shutil.rmtree
+        self.module.move       = shutil.move
+
+        # Useful directories within the prefix
+        self.module.prefix  = self.prefix
+        self.module.bin     = new_path(self.prefix, 'bin')
+        self.module.sbin    = new_path(self.prefix, 'sbin')
+        self.module.etc     = new_path(self.prefix, 'etc')
+        self.module.include = new_path(self.prefix, 'include')
+        self.module.lib     = new_path(self.prefix, 'lib')
+        self.module.libexec = new_path(self.prefix, 'libexec')
+        self.module.share   = new_path(self.prefix, 'share')
+        self.module.doc     = new_path(self.module.share, 'doc')
+        self.module.info    = new_path(self.module.share, 'info')
+        self.module.man     = new_path(self.module.share, 'man')
+        self.module.man1    = new_path(self.module.man, 'man1')
+        self.module.man2    = new_path(self.module.man, 'man2')
+        self.module.man3    = new_path(self.module.man, 'man3')
+        self.module.man4    = new_path(self.module.man, 'man4')
+        self.module.man5    = new_path(self.module.man, 'man5')
+        self.module.man6    = new_path(self.module.man, 'man6')
+        self.module.man7    = new_path(self.module.man, 'man7')
+        self.module.man8    = new_path(self.module.man, 'man8')
+
+
+    @property
+    def dependents(self):
+        """List of names of packages that depend on this one."""
+        if self._dependents is None:
+            packages.compute_dependents()
+        return tuple(self._dependents)
+
+
+    @property
+    def installed(self):
+        return os.path.exists(self.prefix)
+
+
+    @property
+    def installed_dependents(self):
+        installed = [d for d in self.dependents if packages.get(d).installed]
+        all_deps = []
+        for d in installed:
+            all_deps.append(d)
+            all_deps.extend(packages.get(d).installed_dependents)
+        return tuple(all_deps)
+
+
+    @property
+    def all_dependents(self):
+        all_deps = list(self.dependents)
+        for pkg in self.dependents:
+            all_deps.extend(packages.get(pkg).all_dependents)
+        return tuple(all_deps)
+
 
     @property
     def stage(self):
-        return Stage(self.stage_name)
+        return Stage(self.stage_name, self.url)
+
 
     @property
     def stage_name(self):
         return "%s-%s" % (self.name, self.version)
 
+
+    @property
+    def platform_path(self):
+        """Directory for binaries for the current platform."""
+        return new_path(install_path, self.arch)
+
+
+    @property
+    def package_path(self):
+        """Directory for different versions of this package.  Lives just above prefix."""
+        return new_path(self.platform_path, self.name)
+
+
+    @property
+    def installed_versions(self):
+        return [ver for ver in os.listdir(self.package_path)
+                if os.path.isdir(new_path(self.package_path, ver))]
+
+
     @property
     def prefix(self):
-        return new_path(install_path, self.stage_name)
+        """Packages are installed in $spack_prefix/opt/<sys_type>/<name>/<version>"""
+        return new_path(self.package_path, self.version)
+
+
+    def remove_prefix(self):
+        """Removes the prefix for a package along with any empty parent directories."""
+        shutil.rmtree(self.prefix, True)
+        for dir in (self.package_path, self.platform_path):
+            if not os.listdir(dir):
+                os.rmdir(dir)
+            else:
+                break
+
 
     def do_fetch(self):
         """Creates a stage directory and downloads the taball for this package.
@@ -62,49 +215,28 @@ def do_fetch(self):
         """
         stage = self.stage
         stage.setup()
-        stage.chdir()
+        stage.fetch()
 
-        archive_file = os.path.basename(self.url)
-        if not os.path.exists(archive_file):
-            tty.msg("Fetching %s" % self.url)
-
-            # Run curl but grab the mime type from the http headers
-            headers = curl('-#', '-O', '-D', '-', self.url, return_output=True)
-
-            # output this if we somehow got an HTML file rather than the archive we
-            # asked for.
-            if re.search(r'Content-Type: text/html', headers):
-                tty.warn("The contents of '%s' look like HTML.  The checksum will "+
-                         "likely fail.  Use 'spack clean %s' to delete this file. "
-                         "The fix the gateway issue and install again." % (archive_file, self.name))
-
-            if not os.path.exists(archive_file):
-                tty.die("Failed to download '%s'!" % self.url)
-        else:
-            tty.msg("Already downloaded %s." % self.name)
-
-        archive_md5 = md5(archive_file)
+        archive_md5 = md5(stage.archive_file)
         if archive_md5 != self.md5:
             tty.die("MD5 Checksum failed for %s.  Expected %s but got %s."
                     % (self.name, self.md5, archive_md5))
 
-        return archive_file
 
     def do_stage(self):
         """Unpacks the fetched tarball, then changes into the expanded tarball directory."""
-        archive_file = self.do_fetch()
+        self.do_fetch()
         stage = self.stage
 
-        archive_dir = stage.archive_path
+        archive_dir = stage.expanded_archive_path
         if not archive_dir:
-            tty.msg("Staging archive: '%s'" % archive_file)
-            decompress = decompressor_for(archive_file)
-            decompress(archive_file)
+            tty.msg("Staging archive: '%s'" % stage.archive_file)
+            stage.expand_archive()
         else:
-            tty.msg("Alredy staged %s" % self.name)
-
+            tty.msg("Already staged %s" % self.name)
         stage.chdir_to_archive()
 
+
     def do_install(self):
         """This class should call this version of the install method.
            Package implementations should override install().
@@ -114,17 +246,55 @@ def do_install(self):
             tty.pkg(self.prefix)
             return
 
+        if not self.ignore_dependencies:
+            self.do_install_dependencies()
+
         self.do_stage()
+        self.setup_install_environment()
+
+        try:
+            self.install(self.prefix)
+            if not os.path.isdir(self.prefix):
+                tty.die("Install failed for %s.  No install dir created." % self.name)
+        except Exception, e:
+            # Blow away the install tree if anything goes wrong.
+            self.remove_prefix()
+            tty.die("Install failed for %s" % self.name, e.message)
 
-        # Populate the module scope of install() with some useful functions.
-        # This makes things easier for package writers.
-        self.module.configure = which("configure", [self.stage.archive_path])
-        self.module.cmake = which("cmake")
 
-        self.install(self.prefix)
         tty.msg("Successfully installed %s" % self.name)
         tty.pkg(self.prefix)
 
+
+    def setup_install_environment(self):
+        """This ensures a clean install environment when we build packages."""
+        pop_keys(os.environ, "LD_LIBRARY_PATH", "LD_RUN_PATH", "DYLD_LIBRARY_PATH")
+
+        # Add spack environment at front of path and pass the
+        # lib location along so the compiler script can find spack
+        os.environ["SPACK_LIB"] = lib_path
+
+        # Fix for case-insensitive file systems.  Conflicting links are
+        # in directories called "case*" within the env directory.
+        env_paths = [env_path]
+        for file in os.listdir(env_path):
+            path = new_path(env_path, file)
+            if file.startswith("case") and os.path.isdir(path):
+                env_paths.append(path)
+        path_prepend("PATH", *env_paths)
+        path_prepend("SPACK_ENV_PATH", *env_paths)
+
+        # Pass along paths of dependencies here
+        for dep in self.dependencies:
+            path_prepend("SPACK_DEPENDENCIES", dep.package.prefix)
+
+
+    def do_install_dependencies(self):
+        # Pass along paths of dependencies here
+        for dep in self.dependencies:
+            dep.package.do_install()
+
+
     @property
     def module(self):
         """Use this to add variables to the class's module's scope.
@@ -133,36 +303,49 @@ def module(self):
         return __import__(self.__class__.__module__,
                           fromlist=[self.__class__.__name__])
 
+
     def install(self, prefix):
         """Package implementations override this with their own build configuration."""
         tty.die("Packages must provide an install method!")
 
+
     def do_uninstall(self):
-        self.uninstall(self.prefix)
+        if not os.path.exists(self.prefix):
+            tty.die(self.name + " is not installed.")
+
+        if not self.ignore_dependencies:
+            deps = self.installed_dependents
+            if deps: tty.die(
+                "Cannot uninstall %s. The following installed packages depend on it:"
+                % self.name, " ".join(deps))
+
+        self.remove_prefix()
         tty.msg("Successfully uninstalled %s." % self.name)
 
-    def uninstall(self, prefix):
-        """By default just blows the install dir away."""
-        shutil.rmtree(self.prefix, True)
 
     def do_clean(self):
-        self.clean()
+        if self.stage.expanded_archive_path:
+            self.stage.chdir_to_archive()
+            self.clean()
+
 
     def clean(self):
         """By default just runs make clean.  Override if this isn't good."""
-        stage = self.stage
-        if stage.archive_path:
-            stage.chdir_to_archive()
-            try:
-                make("clean")
-                tty.msg("Successfully cleaned %s" % self.name)
-            except subprocess.CalledProcessError:
-                # Might not be configured.  Ignore.
-                pass
+        try:
+            make = make_make()
+            make('clean')
+            tty.msg("Successfully cleaned %s" % self.name)
+        except subprocess.CalledProcessError, e:
+            tty.warn("Warning: 'make clean' didn't work.  Consider 'spack clean --work'.")
 
-    def do_clean_all(self):
+
+    def do_clean_work(self):
+        """By default just blows away the stage directory and re-stages."""
+        self.stage.restage()
+
+
+    def do_clean_dist(self):
+        """Removes the stage directory where this package was built."""
         if os.path.exists(self.stage.path):
             self.stage.destroy()
         tty.msg("Successfully cleaned %s" % self.name)
-
-
diff --git a/lib/spack/spack/__init__.py b/lib/spack/spack/__init__.py
index 15dc99c866..81dfd0c8eb 100644
--- a/lib/spack/spack/__init__.py
+++ b/lib/spack/spack/__init__.py
@@ -1,5 +1,6 @@
 
 from globals import *
-from fileutils import *
+from utils import *
+from exception import *
 
 from Package import Package, depends_on
diff --git a/lib/spack/spack/arch.py b/lib/spack/spack/arch.py
new file mode 100644
index 0000000000..88f04cb478
--- /dev/null
+++ b/lib/spack/spack/arch.py
@@ -0,0 +1,34 @@
+import os
+import platform
+
+from version import Version
+from utils import memoized
+
+instances = {}
+macos_versions = [
+    ('10.8', 'mountain_lion'),
+    ('10.7', 'lion'),
+    ('10.6', 'snow_leopard'),
+    ('10.5', 'leopard')]
+
+
+class SysType(object):
+    def __init__(self, arch_string):
+        self.arch_string = arch_string
+
+    def __repr__(self):
+        return self.arch_string
+
+    def __str__(self):
+        return self.__repr__()
+
+@memoized
+def sys_type():
+    stype = os.environ.get('SYS_TYPE')
+    if stype:
+        return SysType(stype)
+    elif platform.mac_ver()[0]:
+        version = Version(platform.mac_ver()[0])
+        for mac_ver, name in macos_versions:
+            if version >= Version(mac_ver):
+                return SysType(name)
diff --git a/lib/spack/spack/attr.py b/lib/spack/spack/attr.py
index 03fc6e1463..2da77aae54 100644
--- a/lib/spack/spack/attr.py
+++ b/lib/spack/spack/attr.py
@@ -6,3 +6,9 @@ def required(obj, attr_name):
         tty.die("No required attribute '%s' in class '%s'"
                 % (attr_name, obj.__class__.__name__))
 
+
+def setdefault(obj, name, value):
+    """Like dict.setdefault, but for objects."""
+    if not hasattr(obj, name):
+        setattr(obj, name, value)
+    return getattr(obj, name)
diff --git a/lib/spack/spack/cmd/__init__.py b/lib/spack/spack/cmd/__init__.py
index 20c4685e1b..8d2f263b63 100644
--- a/lib/spack/spack/cmd/__init__.py
+++ b/lib/spack/spack/cmd/__init__.py
@@ -4,16 +4,20 @@
 import spack
 import spack.tty as tty
 
-SETUP_PARSER = "setup_parser"
+# Patterns to ignore in the commands directory when looking for commands.
+ignore_files = r'^\.|^__init__.py$|^#'
+
+setup_parser = "setup_parser"
 command_path = os.path.join(spack.lib_path, "spack", "cmd")
 
 commands = []
 for file in os.listdir(command_path):
-    if file.endswith(".py") and not file == "__init__.py":
+    if file.endswith(".py") and not re.search(ignore_files, file):
         cmd = re.sub(r'.py$', '', file)
         commands.append(cmd)
 commands.sort()
 
+
 def null_op(*args):
     pass
 
@@ -21,8 +25,8 @@ def null_op(*args):
 def get_module(name):
     """Imports the module for a particular command name and returns it."""
     module_name = "%s.%s" % (__name__, name)
-    module = __import__(module_name, fromlist=[name, SETUP_PARSER], level=0)
-    module.setup_parser = getattr(module, SETUP_PARSER, null_op)
+    module = __import__(module_name, fromlist=[name, setup_parser], level=0)
+    module.setup_parser = getattr(module, setup_parser, null_op)
 
     if not hasattr(module, name):
         tty.die("Command module %s (%s) must define function '%s'."
diff --git a/lib/spack/spack/cmd/arch.py b/lib/spack/spack/cmd/arch.py
deleted file mode 100644
index fdbed800b1..0000000000
--- a/lib/spack/spack/cmd/arch.py
+++ /dev/null
@@ -1,12 +0,0 @@
-from spack import *
-import spack.version as version
-
-import multiprocessing
-import platform
-
-def arch(args):
-    print multiprocessing.cpu_count()
-    print platform.mac_ver()
-
-
-    print version.canonical(platform.mac_ver()[0])
diff --git a/lib/spack/spack/cmd/clean.py b/lib/spack/spack/cmd/clean.py
index eecfb011e3..f3243f57cc 100644
--- a/lib/spack/spack/cmd/clean.py
+++ b/lib/spack/spack/cmd/clean.py
@@ -1,16 +1,21 @@
 import spack.packages as packages
 
 def setup_parser(subparser):
-    subparser.add_argument('name', help="name of package to clean")
-    subparser.add_argument('-a', "--all", action="store_true", dest="all",
-                           help="delete the entire stage directory")
+    subparser.add_argument('names', nargs='+', help="name(s) of package(s) to clean")
+    subparser.add_mutually_exclusive_group()
+    subparser.add_argument('-c', "--clean", action="store_true", dest='clean',
+                           help="run make clean in the stage directory (default)")
+    subparser.add_argument('-w', "--work", action="store_true", dest='work',
+                           help="delete and re-expand the entire stage directory")
+    subparser.add_argument('-d', "--dist", action="store_true", dest='dist',
+                           help="delete the downloaded archive.")
 
 def clean(args):
-    package_class = packages.get(args.name)
-    package = package_class()
-    if args.all:
-        package.do_clean_all()
-    else:
-        package.do_clean()
-
-
+    for name in args.names:
+        package = packages.get(name)
+        if args.dist:
+            package.do_clean_dist()
+        elif args.work:
+            package.do_clean_work()
+        else:
+            package.do_clean()
diff --git a/lib/spack/spack/cmd/create.py b/lib/spack/spack/cmd/create.py
index 3354831508..7407ae7ee3 100644
--- a/lib/spack/spack/cmd/create.py
+++ b/lib/spack/spack/cmd/create.py
@@ -1,27 +1,30 @@
 import string
+import os
 
 import spack
 import spack.packages as packages
 import spack.tty as tty
 import spack.version
 
-pacakge_tempate = string.Template("""\
+from spack.stage import Stage
+from contextlib import closing
+
+package_template = string.Template("""\
 from spack import *
 
-class $name(Package):
-    homepage = "${homepage}"
+class ${class_name}(Package):
+    homepage = "http://www.example.com"
     url      = "${url}"
     md5      = "${md5}"
 
-    def install(self):
-        # Insert your installation code here.
-        pass
+    def install(self, prefix):
+        # Insert the configure line for your build system here.
+        configure("--prefix=%s" % prefix)
+        # cmake(".", *std_cmake_args)
+        make()
+        make("install")
 """)
 
-def create_template(name):
-    class_name = name.capitalize()
-    return new_pacakge_tempate % class_name
-
 
 def setup_parser(subparser):
     subparser.add_argument('url', nargs='?', help="url of package archive")
@@ -30,28 +33,42 @@ def setup_parser(subparser):
 def create(args):
     url = args.url
 
-    version = spack.version.parse(url)
-    if not version:
-        tty.die("Couldn't figure out a version string from '%s'." % url)
-
-
-
-    # By default open the directory where packages live.
+    # Try to deduce name and version of the new package from the URL
+    name, version = spack.version.parse(url)
     if not name:
-        path = spack.packages_path
-    else:
-        path = packages.filename_for(name)
+        print "Couldn't guess a name for this package."
+        while not name:
+            new_name = raw_input("Name: ")
+            if packages.valid_name(name):
+                name = new_name
+            else:
+                print "Package names must contain letters, numbers, and '_' or '-'"
 
-        if os.path.exists(path):
-            if not os.path.isfile(path):
-                tty.die("Something's wrong.  '%s' is not a file!" % path)
-            if not os.access(path, os.R_OK|os.W_OK):
-                tty.die("Insufficient permissions on '%s'!" % path)
-        else:
-            tty.msg("Editing new file: '%s'." % path)
-            file = open(path, "w")
-            file.write(create_template(name))
-            file.close()
+    if not version:
+        tty.die("Couldn't guess a version string from %s." % url)
+
+    path = packages.filename_for(name)
+    if os.path.exists(path):
+        tty.die("%s already exists." % path)
+
+    # make a stage and fetch the archive.
+    try:
+        stage = Stage(name, url)
+        archive_file = stage.fetch()
+    except spack.FailedDownloadException, e:
+        tty.die(e.message)
+
+    md5 = spack.md5(archive_file)
+    class_name = packages.class_for(name)
+
+    # Write outa template for the file
+    tty.msg("Editing %s." % path)
+    with closing(open(path, "w")) as pkg_file:
+        pkg_file.write(
+            package_template.substitute(
+                class_name=class_name,
+                url=url,
+                md5=md5))
 
     # If everything checks out, go ahead and edit.
     spack.editor(path)
diff --git a/lib/spack/spack/cmd/edit.py b/lib/spack/spack/cmd/edit.py
index 6efcc5487e..13ebd9b073 100644
--- a/lib/spack/spack/cmd/edit.py
+++ b/lib/spack/spack/cmd/edit.py
@@ -3,29 +3,12 @@
 import spack.packages as packages
 import spack.tty as tty
 
-new_pacakge_tempate = """\
-from spack import *
-
-class %s(Package):
-    homepage = "https://www.example.com"
-    url      = "https://www.example.com/download/example-1.0.tar.gz"
-    md5      = "nomd5"
-
-    def install(self):
-        # Insert your installation code here.
-        pass
-
-"""
-
-def create_template(name):
-    class_name = name.capitalize()
-    return new_pacakge_tempate % class_name
-
 
 def setup_parser(subparser):
     subparser.add_argument(
         'name', nargs='?', default=None, help="name of package to edit")
 
+
 def edit(args):
     name = args.name
 
@@ -41,10 +24,7 @@ def edit(args):
             if not os.access(path, os.R_OK|os.W_OK):
                 tty.die("Insufficient permissions on '%s'!" % path)
         else:
-            tty.msg("Editing new file: '%s'." % path)
-            file = open(path, "w")
-            file.write(create_template(name))
-            file.close()
+            tty.die("No package for %s.  Use spack create.")
 
     # If everything checks out, go ahead and edit.
     spack.editor(path)
diff --git a/lib/spack/spack/cmd/fetch.py b/lib/spack/spack/cmd/fetch.py
index 8682a76a1b..310ad343cc 100644
--- a/lib/spack/spack/cmd/fetch.py
+++ b/lib/spack/spack/cmd/fetch.py
@@ -4,6 +4,5 @@ def setup_parser(subparser):
     subparser.add_argument('name', help="name of package to fetch")
 
 def fetch(args):
-    package_class = packages.get(args.name)
-    package = package_class()
+    package = packages.get(args.name)
     package.do_fetch()
diff --git a/lib/spack/spack/cmd/graph.py b/lib/spack/spack/cmd/graph.py
new file mode 100644
index 0000000000..2796d07f35
--- /dev/null
+++ b/lib/spack/spack/cmd/graph.py
@@ -0,0 +1,6 @@
+import spack
+import spack.packages as packages
+
+
+def graph(args):
+    packages.graph_dependencies()
diff --git a/lib/spack/spack/cmd/install.py b/lib/spack/spack/cmd/install.py
index f946e49ba3..eab9d3969b 100644
--- a/lib/spack/spack/cmd/install.py
+++ b/lib/spack/spack/cmd/install.py
@@ -1,11 +1,14 @@
+import spack
 import spack.packages as packages
 
 def setup_parser(subparser):
-    subparser.add_argument('name', help="name of package to install")
+    subparser.add_argument('names', nargs='+', help="name(s) of package(s) to install")
+    subparser.add_argument('-i', '--ignore-dependencies',
+                           action='store_true', dest='ignore_dependencies',
+                           help="Do not try to install dependencies of requested packages.")
 
 def install(args):
-    package_class = packages.get(args.name)
-    package = package_class()
-    package.do_install()
-
-
+    spack.ignore_dependencies = args.ignore_dependencies
+    for name in args.names:
+        package = packages.get(name)
+        package.do_install()
diff --git a/lib/spack/spack/cmd/list.py b/lib/spack/spack/cmd/list.py
new file mode 100644
index 0000000000..dcba730c28
--- /dev/null
+++ b/lib/spack/spack/cmd/list.py
@@ -0,0 +1,22 @@
+import spack
+import spack.packages as packages
+from spack.colify import colify
+
+
+def setup_parser(subparser):
+    subparser.add_argument('-i', '--installed', action='store_true', dest='installed',
+                           help='List installed packages for each platform along with versions.')
+
+
+def list(args):
+    if args.installed:
+        pkgs = packages.installed_packages()
+        for sys_type in pkgs:
+            print "%s:" % sys_type
+            package_vers = []
+            for pkg in pkgs[sys_type]:
+                pv = [pkg.name + "/" + v for v in pkg.installed_versions]
+                package_vers.extend(pv)
+            colify(sorted(package_vers), indent=4)
+    else:
+        colify(packages.all_package_names())
diff --git a/lib/spack/spack/cmd/stage.py b/lib/spack/spack/cmd/stage.py
index da7cb4a636..329ac945c7 100644
--- a/lib/spack/spack/cmd/stage.py
+++ b/lib/spack/spack/cmd/stage.py
@@ -4,6 +4,5 @@ def setup_parser(subparser):
     subparser.add_argument('name', help="name of package to stage")
 
 def stage(args):
-    package_class = packages.get(args.name)
-    package = package_class()
+    package = packages.get(args.name)
     package.do_stage()
diff --git a/lib/spack/spack/cmd/uninstall.py b/lib/spack/spack/cmd/uninstall.py
index d618845e55..8b69c437b7 100644
--- a/lib/spack/spack/cmd/uninstall.py
+++ b/lib/spack/spack/cmd/uninstall.py
@@ -1,9 +1,20 @@
 import spack.packages as packages
 
 def setup_parser(subparser):
-    subparser.add_argument('name', help="name of package to uninstall")
+    subparser.add_argument('names', nargs='+', help="name(s) of package(s) to uninstall")
+    subparser.add_argument('-f', '--force', action='store_true', dest='force',
+                           help="Ignore installed packages that depend on this one and remove it anyway.")
 
 def uninstall(args):
-    package_class = packages.get(args.name)
-    package = package_class()
-    package.do_uninstall()
+    # get packages to uninstall as a list.
+    pkgs = [packages.get(name) for name in args.names]
+
+    # Sort packages to be uninstalled by the number of installed dependents
+    # This ensures we do things in the right order
+    def num_installed_deps(pkg):
+        return len(pkg.installed_dependents)
+    pkgs.sort(key=num_installed_deps)
+
+    # Uninstall packages in order now.
+    for pkg in pkgs:
+        pkg.do_uninstall()
diff --git a/lib/spack/spack/colify.py b/lib/spack/spack/colify.py
new file mode 100644
index 0000000000..886928eefb
--- /dev/null
+++ b/lib/spack/spack/colify.py
@@ -0,0 +1,159 @@
+#!/usr/bin/env python
+#
+# colify
+# By Todd Gamblin, tgamblin@llnl.gov
+#
+# Takes a list of items as input and finds a good columnization of them,
+# similar to how gnu ls does.  You can pipe output to this script and
+# get a tight display for it.  This supports both uniform-width and
+# variable-width (tighter) columns.
+#
+# Run colify -h for more information.
+#
+
+def get_terminal_size():
+    import os
+
+    """Get the dimensions of the console."""
+    def ioctl_GWINSZ(fd):
+        try:
+            import fcntl, termios, struct
+            cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
+        except:
+            return
+        return cr
+    cr = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)
+    if not cr:
+        try:
+            fd = os.open(os.ctermid(), os.O_RDONLY)
+            cr = ioctl_GWINSZ(fd)
+            os.close(fd)
+        except:
+            pass
+    if not cr:
+        cr = (os.environ.get('LINES', 25), os.environ.get('COLUMNS', 80))
+
+    return int(cr[1]), int(cr[0])
+
+
+class ColumnConfig:
+    def __init__(self, cols):
+        self.cols = cols
+        self.line_length = 0
+        self.valid = True
+        self.widths = [0] * cols
+
+    def __repr__(self):
+        attrs = [(a,getattr(self, a)) for a in dir(self) if not a.startswith("__")]
+        return "<Config: %s>" % ", ".join("%s: %r" % a for a in attrs)
+
+
+def config_variable_cols(elts, console_cols, padding):
+    # Get a bound on the most columns we could possibly have.
+    lengths = [len(elt) for elt in elts]
+    max_cols = max(1, console_cols / (min(lengths) + padding))
+    max_cols = min(len(elts), max_cols)
+
+    configs = [ColumnConfig(c) for c in xrange(1, max_cols+1)]
+    for elt, length in enumerate(lengths):
+        for i, conf in enumerate(configs):
+            if conf.valid:
+                col = elt / ((len(elts) + i) / (i + 1))
+                padded = length
+                if col < i:
+                    padded += padding
+
+                if conf.widths[col] < padded:
+                    conf.line_length += padded - conf.widths[col]
+                    conf.widths[col] = padded
+                    conf.valid = (conf.line_length < console_cols)
+
+    try:
+        config = next(conf for conf in reversed(configs) if conf.valid)
+    except StopIteration:
+        # If nothing was valid the screen was too narrow -- just use 1 col.
+        config = configs[0]
+
+    config.widths = [w for w in config.widths if w != 0]
+    config.cols = len(config.widths)
+    return config
+
+
+def config_uniform_cols(elts, console_cols, padding):
+    max_len = max(len(elt) for elt in elts) + padding
+    cols = max(1, console_cols / max_len)
+    cols = min(len(elts), cols)
+    config = ColumnConfig(cols)
+    config.widths = [max_len] * cols
+    return config
+
+
+def colify(elts, **options):
+    import sys
+
+    # Get keyword arguments or set defaults
+    output       = options.get("output", sys.stdout)
+    indent       = options.get("indent", 0)
+    padding      = options.get("padding", 2)
+
+    # elts needs to be in an array so we can count the elements
+    if not type(elts) == list:
+        elts = list(elts)
+
+    console_cols = options.get("cols", None)
+    if not console_cols:
+        console_cols, console_rows = get_terminal_size()
+    elif type(console_cols) != int:
+        raise ValueError("Number of columns must be an int")
+    console_cols = max(1, console_cols - indent)
+
+    method = options.get("method", "variable")
+    if method == "variable":
+        config = config_variable_cols(elts, console_cols, padding)
+    elif method == "uniform":
+        config = config_uniform_cols(elts, console_cols, padding)
+    else:
+        raise ValueError("method must be one of: " + allowed_methods)
+
+    cols = config.cols
+    formats = ["%%-%ds" % width for width in config.widths[:-1]]
+    formats.append("%s")  # last column has no trailing space
+
+    rows = (len(elts) + cols - 1) / cols
+    rows_last_col = len(elts) % rows
+
+    for row in xrange(rows):
+        output.write(" " * indent)
+        for col in xrange(cols):
+            elt = col * rows + row
+            output.write(formats[col] % elts[elt])
+
+        output.write("\n")
+        row += 1
+        if row == rows_last_col:
+            cols -= 1
+
+if __name__ == "__main__":
+    import optparse, sys
+
+    cols, rows = get_terminal_size()
+    parser = optparse.OptionParser()
+    parser.add_option("-u", "--uniform", action="store_true", default=False,
+                      help="Use uniformly sized columns instead of variable-size.")
+    parser.add_option("-p", "--padding", metavar="PADDING", action="store",
+                      type=int, default=2, help="Spaces to add between columns.  Default is 2.")
+    parser.add_option("-i", "--indent", metavar="SPACES", action="store",
+                      type=int, default=0, help="Indent the output by SPACES.  Default is 0.")
+    parser.add_option("-w", "--width", metavar="COLS", action="store",
+                      type=int, default=cols, help="Indent the output by SPACES.  Default is 0.")
+    options, args = parser.parse_args()
+
+    method = "variable"
+    if options.uniform:
+        method = "uniform"
+
+    if sys.stdin.isatty():
+        parser.print_help()
+        sys.exit(1)
+    else:
+        colify([line.strip() for line in sys.stdin], method=method, **options.__dict__)
diff --git a/lib/spack/spack/compilation.py b/lib/spack/spack/compilation.py
new file mode 100644
index 0000000000..ee1feabca7
--- /dev/null
+++ b/lib/spack/spack/compilation.py
@@ -0,0 +1,52 @@
+import os
+
+def parse_rpaths(arguments):
+    """argparse, for all its features, cannot understand most compilers'
+       rpath arguments.  This handles '-Wl,', '-Xlinker', and '-R'"""
+    linker_args = []
+    other_args = []
+
+    def get_next(arg, args):
+        """Get an expected next value of an iterator, or die if it's not there"""
+        try:
+            return next(args)
+        except StopIteration:
+            # quietly ignore -rpath and -Xlinker without args.
+            return None
+
+    # Separate linker args from non-linker args
+    args = iter(arguments)
+    for arg in args:
+        if arg.startswith('-Wl,'):
+            sub_args = [sub for sub in arg.replace('-Wl,', '', 1).split(',')]
+            linker_args.extend(sub_args)
+        elif arg == '-Xlinker':
+            target = get_next(arg, args)
+            if target != None:
+                linker_args.append(target)
+        else:
+            other_args.append(arg)
+
+    # Extract all the possible ways rpath can appear in linker args
+    # and append non-rpaths to other_args
+    rpaths = []
+    largs = iter(linker_args)
+    for arg in largs:
+        if arg == '-rpath':
+            target = get_next(arg, largs)
+            if target != None:
+                rpaths.append(target)
+
+        elif arg.startswith('-R'):
+            target = arg.replace('-R', '', 1)
+            if not target:
+                target = get_next(arg, largs)
+                if target == None: break
+
+            if os.path.isdir(target):
+                rpaths.append(target)
+            else:
+                other_args.extend([arg, target])
+        else:
+            other_args.append(arg)
+    return rpaths, other_args
diff --git a/lib/spack/spack/exception.py b/lib/spack/spack/exception.py
new file mode 100644
index 0000000000..815cd9be25
--- /dev/null
+++ b/lib/spack/spack/exception.py
@@ -0,0 +1,23 @@
+
+
+class SpackException(Exception):
+    def __init__(self, message):
+        self.message = message
+
+
+class FailedDownloadException(SpackException):
+    def __init__(self, url):
+        super(FailedDownloadException, self).__init__("Failed to fetch file from URL: " + url)
+        self.url = url
+
+
+class InvalidPackageNameException(SpackException):
+    def __init__(self, name):
+        super(InvalidPackageNameException, self).__init__("Invalid package name: " + name)
+        self.name = name
+
+
+class CommandFailedException(SpackException):
+    def __init__(self, command):
+        super(CommandFailedException, self).__init__("Failed to execute command: " + command)
+        self.command = command
diff --git a/lib/spack/spack/globals.py b/lib/spack/spack/globals.py
index 66cc6ce157..e36305826b 100644
--- a/lib/spack/spack/globals.py
+++ b/lib/spack/spack/globals.py
@@ -4,7 +4,8 @@
 from version import Version
 
 import tty
-from fileutils import *
+from utils import *
+from spack.exception import *
 
 # This lives in $prefix/lib/spac/spack/__file__
 prefix = ancestor(__file__, 4)
@@ -14,6 +15,7 @@
 
 # spack directory hierarchy
 lib_path      = new_path(prefix, "lib", "spack")
+env_path      = new_path(lib_path, "env")
 module_path   = new_path(lib_path, "spack")
 packages_path = new_path(module_path, "packages")
 
@@ -23,20 +25,13 @@
 install_path  = new_path(prefix, "opt")
 
 # Version information
-version = Version("0.1")
+spack_version = Version("0.1")
 
 # User's editor from the environment
 editor = Executable(os.environ.get("EDITOR", ""))
 
 # Curl tool for fetching files.
-curl = which("curl")
-if not curl:
-    tty.die("spack requires curl.  Make sure it is in your path.")
-
-make = which("make")
-make.add_default_arg("-j%d" % multiprocessing.cpu_count())
-if not make:
-    tty.die("spack requires make.  Make sure it is in your path.")
+curl = which("curl", required=True)
 
 verbose = False
 debug = False
diff --git a/lib/spack/spack/packages/__init__.py b/lib/spack/spack/packages/__init__.py
index 2aadfc612f..21b32b43cc 100644
--- a/lib/spack/spack/packages/__init__.py
+++ b/lib/spack/spack/packages/__init__.py
@@ -1,17 +1,86 @@
-import spack
-from spack.fileutils import *
-
 import re
+import os
+import sys
+import string
 import inspect
+import glob
+
+import spack
+from spack.utils import *
+import spack.arch as arch
+import spack.version as version
+import spack.attr as attr
+
+# Valid package names
+valid_package = r'^[a-zA-Z0-9_-]*$'
+
+# Don't allow consecutive [_-] in package names
+invalid_package = r'[_-][_-]+'
+
+instances = {}
 
 
-def filename_for(package):
+def valid_name(pkg):
+    return re.match(valid_package, pkg) and not re.search(invalid_package, pkg)
+
+
+def validate_name(pkg):
+    if not valid_name(pkg):
+        raise spack.InvalidPackageNameException(pkg)
+
+
+def filename_for(pkg):
     """Get the filename where a package name should be stored."""
-    return new_path(spack.packages_path, "%s.py" % package.lower())
+    validate_name(pkg)
+    return new_path(spack.packages_path, "%s.py" % pkg)
 
 
-def get(name):
-    file = filename_for(name)
+def installed_packages(**kwargs):
+    """Returns a dict from SysType to lists of Package objects."""
+    list_installed = kwargs.get('installed', False)
+
+    pkgs = {}
+    if not os.path.isdir(spack.install_path):
+        return pkgs
+
+    for sys_type in os.listdir(spack.install_path):
+        sys_type = arch.SysType(sys_type)
+        sys_path = new_path(spack.install_path, sys_type)
+        pkgs[sys_type] = [get(pkg) for pkg in os.listdir(sys_path)
+                          if os.path.isdir(new_path(sys_path, pkg))]
+    return pkgs
+
+
+def all_package_names():
+    """Generator function for all packages."""
+    os.chdir(spack.packages_path)
+    for name in glob.glob("*.py"):
+        if name != '__init__.py':
+            yield re.sub('.py$', '', name)
+
+
+def all_packages():
+    for name in all_package_names():
+        yield get(name)
+
+
+def class_for(pkg):
+    """Get a name for the class the package file should contain.  Note that
+       conflicts don't matter because the classes are in different modules.
+    """
+    validate_name(pkg)
+    class_name = string.capwords(pkg.replace('_', '-'), '-')
+
+    # If a class starts with a number, prefix it with Number_ to make it a valid
+    # Python class name.
+    if re.match(r'^[0-9]', class_name):
+        class_name = "Number_%s" % class_name
+
+    return class_name
+
+
+def get_class(pkg):
+    file = filename_for(pkg)
 
     if os.path.exists(file):
         if not os.path.isfile(file):
@@ -19,17 +88,63 @@ def get(name):
         if not os.access(file, os.R_OK):
             tty.die("Cannot read '%s'!" % file)
 
-    class_name = name.capitalize()
+    class_name = pkg.capitalize()
     try:
-        module_name = "%s.%s" % (__name__, name)
+        module_name = "%s.%s" % (__name__, pkg)
         module = __import__(module_name, fromlist=[class_name])
     except ImportError, e:
-        tty.die("Error while importing %s.%s:\n%s" % (name, class_name, e.message))
+        tty.die("Error while importing %s.%s:\n%s" % (pkg, class_name, e.message))
 
     klass = getattr(module, class_name)
     if not inspect.isclass(klass):
-        tty.die("%s.%s is not a class" % (name, class_name))
+        tty.die("%s.%s is not a class" % (pkg, class_name))
 
     return klass
 
 
+def get(pkg, arch=arch.sys_type()):
+    key = (pkg, arch)
+    if not key in instances:
+        package_class = get_class(pkg)
+        instances[key] = package_class(arch)
+    return instances[key]
+
+
+def compute_dependents():
+    """Reads in all package files and sets dependence information on
+       Package objects in memory.
+    """
+    for pkg in all_packages():
+        if pkg._dependents is None:
+            pkg._dependents = []
+
+        for dep in pkg.dependencies:
+            dpkg = get(dep.name)
+            if dpkg._dependents is None:
+                dpkg._dependents = []
+            dpkg._dependents.append(pkg.name)
+
+
+def graph_dependencies(out=sys.stdout):
+    """Print out a graph of all the dependencies between package.
+       Graph is in dot format."""
+    out.write('digraph G {\n')
+    out.write('  label = "Spack Dependencies"\n')
+    out.write('  labelloc = "b"\n')
+    out.write('  rankdir = "LR"\n')
+    out.write('  ranksep = "5"\n')
+    out.write('\n')
+
+    def quote(string):
+        return '"%s"' % string
+
+    deps = []
+    for pkg in all_packages():
+        out.write('  %-30s [label="%s"]\n' % (quote(pkg.name), pkg.name))
+        for dep in pkg.dependencies:
+            deps.append((pkg.name, dep.name))
+    out.write('\n')
+
+    for pair in deps:
+        out.write('  "%s" -> "%s"\n' % pair)
+    out.write('}\n')
diff --git a/lib/spack/spack/packages/libdwarf.py b/lib/spack/spack/packages/libdwarf.py
new file mode 100644
index 0000000000..747ac1dd1f
--- /dev/null
+++ b/lib/spack/spack/packages/libdwarf.py
@@ -0,0 +1,41 @@
+from spack import *
+import os
+
+# Only build certain parts of dwarf because the other ones break.
+dwarf_dirs = ['libdwarf', 'dwarfdump2']
+
+class Libdwarf(Package):
+    homepage = "http://www.example.com"
+    url      = "http://reality.sgiweb.org/davea/libdwarf-20130207.tar.gz"
+    md5      = "64b42692e947d5180e162e46c689dfbf"
+
+    depends_on("libelf")
+
+    def clean(self):
+        for dir in dwarf_dirs:
+            with working_dir(dir):
+                if os.path.exists('Makefile'):
+                    make('clean')
+
+
+    def install(self, prefix):
+        make.add_default_arg('ARFLAGS=rcs')
+
+        for dir in dwarf_dirs:
+            with working_dir(dir):
+                #configure("--prefix=%s" % prefix, '--enable-shared')
+                configure("--prefix=%s" % prefix)
+                make()
+
+        # Dwarf doesn't provide an install.  Annoying.
+        mkdirp(bin, include, lib, man1)
+        with working_dir('libdwarf'):
+            install('libdwarf.a',  lib)
+            #install('libdwarf.so', lib)
+            install('libdwarf.h',  include)
+            install('dwarf.h',     include)
+
+        with working_dir('dwarfdump2'):
+            install('dwarfdump',     bin)
+            install('dwarfdump.conf', lib)
+            install('dwarfdump.1',    man1)
diff --git a/lib/spack/spack/packages/libelf.py b/lib/spack/spack/packages/libelf.py
new file mode 100644
index 0000000000..7d2aca2102
--- /dev/null
+++ b/lib/spack/spack/packages/libelf.py
@@ -0,0 +1,13 @@
+from spack import *
+
+class Libelf(Package):
+    homepage = "http://www.mr511.de/software/english.html"
+    url      = "http://www.mr511.de/software/libelf-0.8.13.tar.gz"
+    md5      = "4136d7b4c04df68b686570afa26988ac"
+
+    def install(self, prefix):
+        configure("--prefix=%s" % prefix,
+                  "--disable-dependency-tracking",
+                  "--disable-debug")
+        make()
+        make("install")
diff --git a/lib/spack/spack/stage.py b/lib/spack/spack/stage.py
index 8585c75976..93708a1efe 100644
--- a/lib/spack/spack/stage.py
+++ b/lib/spack/spack/stage.py
@@ -1,7 +1,9 @@
 import os
+import re
 import shutil
 
 import spack
+import packages
 import tty
 
 
@@ -11,8 +13,9 @@ def ensure_access(dir=spack.stage_path):
 
 
 class Stage(object):
-    def __init__(self, stage_name):
+    def __init__(self, stage_name, url):
         self.stage_name = stage_name
+        self.url = url
 
     @property
     def path(self):
@@ -30,7 +33,15 @@ def setup(self):
 
 
     @property
-    def archive_path(self):
+    def archive_file(self):
+        path = os.path.join(self.path, os.path.basename(self.url))
+        if os.path.exists(path):
+            return path
+        return None
+
+
+    @property
+    def expanded_archive_path(self):
         """"Returns the path to the expanded archive directory if it's expanded;
             None if the archive hasn't been expanded.
         """
@@ -43,17 +54,54 @@ def archive_path(self):
 
     def chdir(self):
         """Changes directory to the stage path.  Or dies if it is not set up."""
+        self.setup()
         if os.path.isdir(self.path):
             os.chdir(self.path)
         else:
-            tty.die("Attempt to chdir to stage before setup.")
+            tty.die("Setup failed: no such directory: " + self.path)
+
+
+    def fetch(self):
+        """Downloads the file at URL to the stage.  Returns true if it was downloaded,
+           false if it already existed."""
+        self.chdir()
+        if self.archive_file:
+            tty.msg("Already downloaded %s." % self.archive_file)
+
+        else:
+            tty.msg("Fetching %s" % self.url)
+
+            # Run curl but grab the mime type from the http headers
+            headers = spack.curl('-#', '-O', '-D', '-', self.url, return_output=True)
+
+            # output this if we somehow got an HTML file rather than the archive we
+            # asked for.
+            if re.search(r'Content-Type: text/html', headers):
+                tty.warn("The contents of '%s' look like HTML.  The checksum will "+
+                         "likely fail.  Use 'spack clean %s' to delete this file. "
+                         "The fix the gateway issue and install again." % (self.archive_file, self.name))
+
+        if not self.archive_file:
+            raise FailedDownloadException(url)
+
+        return self.archive_file
+
+
+    def expand_archive(self):
+        self.chdir()
+
+        if not self.archive_file:
+            tty.die("Attempt to expand archive before fetching.")
+
+        decompress = spack.decompressor_for(self.archive_file)
+        decompress(self.archive_file)
 
 
     def chdir_to_archive(self):
         """Changes directory to the expanded archive directory if it exists.
            Dies with an error otherwise.
         """
-        path = self.archive_path
+        path = self.expanded_archive_path
         if not path:
             tty.die("Attempt to chdir before expanding archive.")
         else:
@@ -62,6 +110,16 @@ def chdir_to_archive(self):
                 tty.die("Archive was empty for '%s'" % self.name)
 
 
+    def restage(self):
+        """Removes the expanded archive path if it exists, then re-expands the archive."""
+        if not self.archive_file:
+            tty.die("Attempt to restage when not staged.")
+
+        if self.expanded_archive_path:
+            shutil.rmtree(self.expanded_archive_path, True)
+        self.expand_archive()
+
+
     def destroy(self):
         """Blows away the stage directory.  Can always call setup() again."""
         if os.path.exists(self.path):
diff --git a/lib/spack/spack/test/test_versions.py b/lib/spack/spack/test/test_versions.py
index e7ebae630b..ecf98c2dbb 100755
--- a/lib/spack/spack/test/test_versions.py
+++ b/lib/spack/spack/test/test_versions.py
@@ -10,20 +10,24 @@
 class VersionTest(unittest.TestCase):
 
     def assert_not_detected(self, string):
-        self.assertIsNone(version.parse(string))
+        name, v = version.parse(string)
+        self.assertIsNone(v)
+
+    def assert_detected(self, name, v, string):
+        parsed_name, parsed_v = version.parse(string)
+        self.assertEqual(parsed_name, name)
+        self.assertEqual(parsed_v, version.Version(v))
 
-    def assert_detected(self, v, string):
-        self.assertEqual(v, version.parse(string))
 
     def test_wwwoffle_version(self):
         self.assert_detected(
-            '2.9h', 'http://www.gedanken.demon.co.uk/download-wwwoffle/wwwoffle-2.9h.tgz')
+            'wwwoffle', '2.9h', 'http://www.gedanken.demon.co.uk/download-wwwoffle/wwwoffle-2.9h.tgz')
 
     def test_version_sourceforge_download(self):
         self.assert_detected(
-            '1.21', 'http://sourceforge.net/foo_bar-1.21.tar.gz/download')
+            'foo_bar', '1.21', 'http://sourceforge.net/foo_bar-1.21.tar.gz/download')
         self.assert_detected(
-            '1.21', 'http://sf.net/foo_bar-1.21.tar.gz/download')
+            'foo_bar', '1.21', 'http://sf.net/foo_bar-1.21.tar.gz/download')
 
     def test_no_version(self):
         self.assert_not_detected('http://example.com/blah.tar')
@@ -31,159 +35,158 @@ def test_no_version(self):
 
     def test_version_all_dots(self):
         self.assert_detected(
-            '1.14','http://example.com/foo.bar.la.1.14.zip')
+            'foo.bar.la', '1.14','http://example.com/foo.bar.la.1.14.zip')
 
     def test_version_underscore_separator(self):
         self.assert_detected(
-            '1.1', 'http://example.com/grc_1.1.tar.gz')
+            'grc', '1.1', 'http://example.com/grc_1.1.tar.gz')
 
     def test_boost_version_style(self):
         self.assert_detected(
-            '1.39.0', 'http://example.com/boost_1_39_0.tar.bz2')
+            'boost', '1.39.0', 'http://example.com/boost_1_39_0.tar.bz2')
 
     def test_erlang_version_style(self):
         self.assert_detected(
-            'R13B', 'http://erlang.org/download/otp_src_R13B.tar.gz')
+            'otp', 'R13B', 'http://erlang.org/download/otp_src_R13B.tar.gz')
 
     def test_another_erlang_version_style(self):
         self.assert_detected(
-            'R15B01', 'https://github.com/erlang/otp/tarball/OTP_R15B01')
+            'otp', 'R15B01', 'https://github.com/erlang/otp/tarball/OTP_R15B01')
 
     def test_yet_another_erlang_version_style(self):
         self.assert_detected(
-            'R15B03-1', 'https://github.com/erlang/otp/tarball/OTP_R15B03-1')
+            'otp', 'R15B03-1', 'https://github.com/erlang/otp/tarball/OTP_R15B03-1')
 
     def test_p7zip_version_style(self):
         self.assert_detected(
-            '9.04',
-            'http://kent.dl.sourceforge.net/sourceforge/p7zip/p7zip_9.04_src_all.tar.bz2')
+            'p7zip', '9.04', 'http://kent.dl.sourceforge.net/sourceforge/p7zip/p7zip_9.04_src_all.tar.bz2')
 
     def test_new_github_style(self):
         self.assert_detected(
-            '1.1.4', 'https://github.com/sam-github/libnet/tarball/libnet-1.1.4')
+            'libnet', '1.1.4', 'https://github.com/sam-github/libnet/tarball/libnet-1.1.4')
 
     def test_gloox_beta_style(self):
         self.assert_detected(
-            '1.0-beta7', 'http://camaya.net/download/gloox-1.0-beta7.tar.bz2')
+            'gloox', '1.0-beta7', 'http://camaya.net/download/gloox-1.0-beta7.tar.bz2')
 
     def test_sphinx_beta_style(self):
         self.assert_detected(
-            '1.10-beta', 'http://sphinxsearch.com/downloads/sphinx-1.10-beta.tar.gz')
+            'sphinx', '1.10-beta', 'http://sphinxsearch.com/downloads/sphinx-1.10-beta.tar.gz')
 
     def test_astyle_verson_style(self):
         self.assert_detected(
-            '1.23', 'http://kent.dl.sourceforge.net/sourceforge/astyle/astyle_1.23_macosx.tar.gz')
+            'astyle', '1.23', 'http://kent.dl.sourceforge.net/sourceforge/astyle/astyle_1.23_macosx.tar.gz')
 
     def test_version_dos2unix(self):
         self.assert_detected(
-            '3.1', 'http://www.sfr-fresh.com/linux/misc/dos2unix-3.1.tar.gz')
+            'dos2unix', '3.1', 'http://www.sfr-fresh.com/linux/misc/dos2unix-3.1.tar.gz')
 
     def test_version_internal_dash(self):
         self.assert_detected(
-            '1.1-2', 'http://example.com/foo-arse-1.1-2.tar.gz')
+            'foo-arse', '1.1-2', 'http://example.com/foo-arse-1.1-2.tar.gz')
 
     def test_version_single_digit(self):
         self.assert_detected(
-            '45', 'http://example.com/foo_bar.45.tar.gz')
+            'foo_bar', '45', 'http://example.com/foo_bar.45.tar.gz')
 
     def test_noseparator_single_digit(self):
         self.assert_detected(
-            '45', 'http://example.com/foo_bar45.tar.gz')
+            'foo_bar', '45', 'http://example.com/foo_bar45.tar.gz')
 
     def test_version_developer_that_hates_us_format(self):
         self.assert_detected(
-            '1.2.3', 'http://example.com/foo-bar-la.1.2.3.tar.gz')
+            'foo-bar-la', '1.2.3', 'http://example.com/foo-bar-la.1.2.3.tar.gz')
 
     def test_version_regular(self):
         self.assert_detected(
-            '1.21', 'http://example.com/foo_bar-1.21.tar.gz')
+            'foo_bar', '1.21', 'http://example.com/foo_bar-1.21.tar.gz')
 
     def test_version_github(self):
         self.assert_detected(
-            '1.0.5', 'http://github.com/lloyd/yajl/tarball/1.0.5')
+            'yajl', '1.0.5', 'http://github.com/lloyd/yajl/tarball/1.0.5')
 
     def test_version_github_with_high_patch_number(self):
         self.assert_detected(
-            '1.2.34', 'http://github.com/lloyd/yajl/tarball/v1.2.34')
+            'yajl', '1.2.34', 'http://github.com/lloyd/yajl/tarball/v1.2.34')
 
     def test_yet_another_version(self):
         self.assert_detected(
-            '0.15.1b', 'http://example.com/mad-0.15.1b.tar.gz')
+            'mad', '0.15.1b', 'http://example.com/mad-0.15.1b.tar.gz')
 
     def test_lame_version_style(self):
         self.assert_detected(
-            '398-2', 'http://kent.dl.sourceforge.net/sourceforge/lame/lame-398-2.tar.gz')
+            'lame', '398-2', 'http://kent.dl.sourceforge.net/sourceforge/lame/lame-398-2.tar.gz')
 
     def test_ruby_version_style(self):
         self.assert_detected(
-            '1.9.1-p243', 'ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p243.tar.gz')
+            'ruby', '1.9.1-p243', 'ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p243.tar.gz')
 
     def test_omega_version_style(self):
         self.assert_detected(
-            '0.80.2', 'http://www.alcyone.com/binaries/omega/omega-0.80.2-src.tar.gz')
+            'omega', '0.80.2', 'http://www.alcyone.com/binaries/omega/omega-0.80.2-src.tar.gz')
 
     def test_rc_style(self):
         self.assert_detected(
-            '1.2.2rc1', 'http://downloads.xiph.org/releases/vorbis/libvorbis-1.2.2rc1.tar.bz2')
+            'libvorbis', '1.2.2rc1', 'http://downloads.xiph.org/releases/vorbis/libvorbis-1.2.2rc1.tar.bz2')
 
     def test_dash_rc_style(self):
         self.assert_detected(
-            '1.8.0-rc1', 'http://ftp.mozilla.org/pub/mozilla.org/js/js-1.8.0-rc1.tar.gz')
+            'js', '1.8.0-rc1', 'http://ftp.mozilla.org/pub/mozilla.org/js/js-1.8.0-rc1.tar.gz')
 
     def test_angband_version_style(self):
         self.assert_detected(
-            '3.0.9b', 'http://rephial.org/downloads/3.0/angband-3.0.9b-src.tar.gz')
+            'angband', '3.0.9b', 'http://rephial.org/downloads/3.0/angband-3.0.9b-src.tar.gz')
 
     def test_stable_suffix(self):
         self.assert_detected(
-            '1.4.14b', 'http://www.monkey.org/~provos/libevent-1.4.14b-stable.tar.gz')
+            'libevent', '1.4.14b', 'http://www.monkey.org/~provos/libevent-1.4.14b-stable.tar.gz')
 
     def test_debian_style_1(self):
         self.assert_detected(
-            '3.03', 'http://ftp.de.debian.org/debian/pool/main/s/sl/sl_3.03.orig.tar.gz')
+            'sl', '3.03', 'http://ftp.de.debian.org/debian/pool/main/s/sl/sl_3.03.orig.tar.gz')
 
     def test_debian_style_2(self):
         self.assert_detected(
-            '1.01b', 'http://ftp.de.debian.org/debian/pool/main/m/mmv/mmv_1.01b.orig.tar.gz')
+            'mmv', '1.01b', 'http://ftp.de.debian.org/debian/pool/main/m/mmv/mmv_1.01b.orig.tar.gz')
 
     def test_imagemagick_style(self):
         self.assert_detected(
-            '6.7.5-7', 'http://downloads.sf.net/project/machomebrew/mirror/ImageMagick-6.7.5-7.tar.bz2')
+            'ImageMagick', '6.7.5-7', 'http://downloads.sf.net/project/machomebrew/mirror/ImageMagick-6.7.5-7.tar.bz2')
 
     def test_dash_version_dash_style(self):
         self.assert_detected(
-            '3.4', 'http://www.antlr.org/download/antlr-3.4-complete.jar')
+            'antlr', '3.4', 'http://www.antlr.org/download/antlr-3.4-complete.jar')
 
     def test_apache_version_style(self):
         self.assert_detected(
-            '1.2.0-rc2', 'http://www.apache.org/dyn/closer.cgi?path=/cassandra/1.2.0/apache-cassandra-1.2.0-rc2-bin.tar.gz')
+            'apache-cassandra', '1.2.0-rc2', 'http://www.apache.org/dyn/closer.cgi?path=/cassandra/1.2.0/apache-cassandra-1.2.0-rc2-bin.tar.gz')
 
     def test_jpeg_style(self):
         self.assert_detected(
-            '8d', 'http://www.ijg.org/files/jpegsrc.v8d.tar.gz')
+            'jpegsrc', '8d', 'http://www.ijg.org/files/jpegsrc.v8d.tar.gz')
 
     def test_more_versions(self):
         self.assert_detected(
-            '1.4.1', 'http://pypy.org/download/pypy-1.4.1-osx.tar.bz2')
+            'pypy', '1.4.1', 'http://pypy.org/download/pypy-1.4.1-osx.tar.bz2')
         self.assert_detected(
-            '0.9.8s', 'http://www.openssl.org/source/openssl-0.9.8s.tar.gz')
+            'openssl', '0.9.8s', 'http://www.openssl.org/source/openssl-0.9.8s.tar.gz')
         self.assert_detected(
-            '1.5E', 'ftp://ftp.visi.com/users/hawkeyd/X/Xaw3d-1.5E.tar.gz')
+            'Xaw3d', '1.5E', 'ftp://ftp.visi.com/users/hawkeyd/X/Xaw3d-1.5E.tar.gz')
         self.assert_detected(
-            '2.1.0beta', 'http://downloads.sourceforge.net/project/fann/fann/2.1.0beta/fann-2.1.0beta.zip')
+            'fann', '2.1.0beta', 'http://downloads.sourceforge.net/project/fann/fann/2.1.0beta/fann-2.1.0beta.zip')
         self.assert_detected(
-            '2.0.1', 'ftp://iges.org/grads/2.0/grads-2.0.1-bin-darwin9.8-intel.tar.gz')
+            'grads', '2.0.1', 'ftp://iges.org/grads/2.0/grads-2.0.1-bin-darwin9.8-intel.tar.gz')
         self.assert_detected(
-            '2.08', 'http://haxe.org/file/haxe-2.08-osx.tar.gz')
+            'haxe', '2.08', 'http://haxe.org/file/haxe-2.08-osx.tar.gz')
         self.assert_detected(
-            '2007f', 'ftp://ftp.cac.washington.edu/imap/imap-2007f.tar.gz')
+            'imap', '2007f', 'ftp://ftp.cac.washington.edu/imap/imap-2007f.tar.gz')
         self.assert_detected(
-            '3.3.12ga7', 'http://sourceforge.net/projects/x3270/files/x3270/3.3.12ga7/suite3270-3.3.12ga7-src.tgz')
+            'suite3270', '3.3.12ga7', 'http://sourceforge.net/projects/x3270/files/x3270/3.3.12ga7/suite3270-3.3.12ga7-src.tgz')
         self.assert_detected(
-            '1.3.6p2', 'http://synergy.googlecode.com/files/synergy-1.3.6p2-MacOSX-Universal.zip')
+            'synergy', '1.3.6p2', 'http://synergy.googlecode.com/files/synergy-1.3.6p2-MacOSX-Universal.zip')
 
 
 
 
 if __name__ == "__main__":
-    unittest.main()
+    unittest.main(failfast=True)
diff --git a/lib/spack/spack/tty.py b/lib/spack/spack/tty.py
index b7b27d2e3b..964e9c8945 100644
--- a/lib/spack/spack/tty.py
+++ b/lib/spack/spack/tty.py
@@ -32,6 +32,11 @@ def msg(msg, *args, **kwargs):
     print "{}==>{} {}{}".format(color, white, str(msg), reset)
     for arg in args: print indent + str(arg)
 
+def info(msg, *args, **kwargs):
+    color = kwargs.get("color", blue)
+    print "{}==>{} {}".format(color, reset, str(msg))
+    for arg in args: print indent + str(arg)
+
 def verbose(*args):
     if spack.verbose: msg(*args, color=green)
 
@@ -46,8 +51,8 @@ def warn(msg, *args):
     print "{}Warning{}: {}".format(yellow, reset, str(msg))
     for arg in args: print indent + str(arg)
 
-def die(msg):
-    error(msg)
+def die(msg, *args):
+    error(msg, *args)
     sys.exit(1)
 
 def pkg(msg):
diff --git a/lib/spack/spack/fileutils.py b/lib/spack/spack/utils.py
similarity index 54%
rename from lib/spack/spack/fileutils.py
rename to lib/spack/spack/utils.py
index 6827e5d1f0..5e135aa799 100644
--- a/lib/spack/spack/fileutils.py
+++ b/lib/spack/spack/utils.py
@@ -1,8 +1,12 @@
 import os
-import subprocess
 import re
+import errno
+import shutil
+import subprocess
+import multiprocessing
 from itertools import product
-from contextlib import closing
+import functools
+from contextlib import closing, contextmanager
 
 import tty
 
@@ -14,17 +18,85 @@
 ALLOWED_ARCHIVE_TYPES = [".".join(l) for l in product(PRE_EXTS, EXTS)] + EXTS
 
 
+def memoized(obj):
+    """Decorator that caches the results of a function, storing them
+       in an attribute of that function."""
+    cache = obj.cache = {}
+    @functools.wraps(obj)
+    def memoizer(*args, **kwargs):
+        if args not in cache:
+            cache[args] = obj(*args, **kwargs)
+            return cache[args]
+    return memoizer
+
+
+def make_make():
+    """Gets a make set up with the proper default arguments."""
+    make = which('make', required=True)
+    if not env_flag("SPACK_NO_PARALLEL_MAKE"):
+        make.add_default_arg("-j%d" % multiprocessing.cpu_count())
+    return make
+
+
+def install(src, dest):
+    tty.info("Installing %s to %s" % (src, dest))
+    shutil.copy(src, dest)
+
+
+@contextmanager
+def working_dir(dirname):
+    orig_dir = os.getcwd()
+    os.chdir(dirname)
+    yield
+    os.chdir(orig_dir)
+
+
+def mkdirp(*paths):
+    for path in paths:
+        if not os.path.exists(path):
+            os.makedirs(path)
+        elif not os.path.isdir(path):
+            raise OSError(errno.EEXIST, "File alredy exists", path)
+
+
+def env_flag(name):
+    if name in os.environ:
+        return os.environ[name].lower() == "true"
+    return False
+
+
+def path_prepend(var_name, *directories):
+    path = os.environ.get(var_name, "")
+    path_str = ":".join(str(dir) for dir in directories)
+    if path == "":
+        os.environ[var_name] = path_str
+    else:
+        os.environ[var_name] = "%s:%s" % (path_str, path)
+
+
+def pop_keys(dictionary, *keys):
+    for key in keys:
+        if key in dictionary:
+            dictionary.pop(key)
+
+
+def remove_items(item_list, *items):
+    for item in items:
+        if item in item_list:
+            item_list.remove(item)
+
+
 def has_whitespace(string):
     return re.search(r'\s', string)
 
 
 def new_path(prefix, *args):
-    path=prefix
+    path=str(prefix)
     for elt in args:
-        path = os.path.join(path, elt)
+        path = os.path.join(path, str(elt))
 
     if has_whitespace(path):
-        tty.die("Invalid path: '%s'.  Use a path without whitespace.")
+        tty.die("Invalid path: '%s'.  Use a path without whitespace." % path)
 
     return path
 
@@ -48,6 +120,7 @@ def add_default_arg(self, arg):
     def __call__(self, *args, **kwargs):
         """Run the executable with subprocess.check_output, return output."""
         return_output = kwargs.get("return_output", False)
+        fail_on_error = kwargs.get("fail_on_error", True)
 
         quoted_args = [arg for arg in args if re.search(r'^"|^\'|"$|\'$', arg)]
         if quoted_args:
@@ -61,24 +134,30 @@ def __call__(self, *args, **kwargs):
 
         if return_output:
             return subprocess.check_output(cmd)
-        else:
+        elif fail_on_error:
             return subprocess.check_call(cmd)
+        else:
+            return subprocess.call(cmd)
 
     def __repr__(self):
         return "<exe: %s>" % self.exe
 
 
-def which(name, path=None):
+def which(name, **kwargs):
     """Finds an executable in the path like command-line which."""
+    path     = kwargs.get('path', os.environ.get('PATH', '').split(os.pathsep))
+    required = kwargs.get('required', False)
+
     if not path:
-        path = os.environ.get('PATH', '').split(os.pathsep)
-    if not path:
-        return None
+        path = []
 
     for dir in path:
         exe = os.path.join(dir, name)
         if os.access(exe, os.X_OK):
             return Executable(exe)
+
+    if required:
+        tty.die("spack requires %s.  Make sure it is in your path." % name)
     return None
 
 
@@ -94,10 +173,9 @@ def stem(path):
 
 def decompressor_for(path):
     """Get the appropriate decompressor for a path."""
-    if which("tar"):
-        return Executable("tar -xf")
-    else:
-        tty.die("spack requires tar.  Make sure it's on your path.")
+    tar = which('tar', required=True)
+    tar.add_default_arg('-xf')
+    return tar
 
 
 def md5(filename, block_size=2**20):
diff --git a/lib/spack/spack/validate.py b/lib/spack/spack/validate.py
index 312517f42a..4b07d75464 100644
--- a/lib/spack/spack/validate.py
+++ b/lib/spack/spack/validate.py
@@ -1,5 +1,5 @@
 import tty
-from fileutils import ALLOWED_ARCHIVE_TYPES
+from utils import ALLOWED_ARCHIVE_TYPES
 from urlparse import urlparse
 
 ALLOWED_SCHEMES    = ["http", "https", "ftp"]
diff --git a/lib/spack/spack/version.py b/lib/spack/spack/version.py
index e3fdd1c826..792a2f6aa8 100644
--- a/lib/spack/spack/version.py
+++ b/lib/spack/spack/version.py
@@ -1,7 +1,7 @@
 import os
 import re
 
-import fileutils
+import utils
 
 class Version(object):
     """Class to represent versions"""
@@ -48,16 +48,16 @@ def intify(part):
     return tuple(intify(v) for v in re.split(r'[_.-]+', v))
 
 
-def parse(spec):
-    """Try to extract a version from a filename.  This is taken largely from
-    Homebrew's Version class."""
+def parse_version(spec):
+    """Try to extract a version from a filename or URL.  This is taken
+    largely from Homebrew's Version class."""
 
     if os.path.isdir(spec):
         stem = os.path.basename(spec)
     elif re.search(r'((?:sourceforge.net|sf.net)/.*)/download$', spec):
-        stem = fileutils.stem(os.path.dirname(spec))
+        stem = utils.stem(os.path.dirname(spec))
     else:
-        stem = fileutils.stem(spec)
+        stem = utils.stem(spec)
 
     version_types = [
         # GitHub tarballs, e.g. v1.2.3
@@ -115,12 +115,36 @@ def parse(spec):
         # e.g. http://www.ijg.org/files/jpegsrc.v8d.tar.gz
         (r'\.v(\d+[a-z]?)', stem)]
 
-    for type in version_types:
-        regex, match_string = type[:2]
+    for vtype in version_types:
+        regex, match_string = vtype[:2]
         match = re.search(regex, match_string)
         if match and match.group(1) is not None:
-            if type[2:]:
-                return Version(type[2](match.group(1)))
+            if vtype[2:]:
+                return Version(vtype[2](match.group(1)))
             else:
                 return Version(match.group(1))
     return None
+
+
+def parse_name(spec, ver=None):
+    if ver is None:
+        ver = parse_version(spec)
+
+    ntypes = (r'/sourceforge/([^/]+)/',
+              r'/([^/]+)/(tarball|zipball)/',
+              r'/([^/]+)[_.-](bin|dist|stable|src|sources)[_.-]%s' % ver,
+              r'/([^/]+)[_.-]v?%s' % ver,
+              r'/([^/]+)%s' % ver,
+              r'^([^/]+)[_.-]v?%s' % ver,
+              r'^([^/]+)%s' % ver)
+
+    for nt in ntypes:
+        match = re.search(nt, spec)
+        if match:
+            return match.group(1)
+    return None
+
+def parse(spec):
+    ver = parse_version(spec)
+    name = parse_name(spec, ver)
+    return (name, ver)