Add --dirty option to spack install.

- Allow install to be run without cleaning the environment.

lib/spack/spack/build_environment.py

@@ -224,9 +224,12 @@ def set_compiler_environment_variables(pkg, env):
     return env
 
 
-def set_build_environment_variables(pkg, env):
+def set_build_environment_variables(pkg, env, dirty=False):
     """
-    This ensures a clean install environment when we build packages
+    This ensures a clean install environment when we build packages.
+
+    Arguments:
+    dirty -- skip unsetting the user's environment settings.
     """
     # Add spack build environment path with compiler wrappers first in
     # the path. We add both spack.env_path, which includes default
@@ -262,14 +265,17 @@ def set_build_environment_variables(pkg, env):
     # Install root prefix
     env.set(SPACK_INSTALL, spack.install_path)
 
-    # Remove these vars from the environment during build because they
-    # can affect how some packages find libraries.  We want to make
-    # sure that builds never pull in unintended external dependencies.
-    env.unset('LD_LIBRARY_PATH')
-    env.unset('LIBRARY_PATH')
-    env.unset('CPATH')
-    env.unset('LD_RUN_PATH')
-    env.unset('DYLD_LIBRARY_PATH')
+    # Stuff in here sanitizes the build environemnt to eliminate
+    # anything the user has set that may interfere.
+    if not dirty:
+        # Remove these vars from the environment during build because they
+        # can affect how some packages find libraries.  We want to make
+        # sure that builds never pull in unintended external dependencies.
+        env.unset('LD_LIBRARY_PATH')
+        env.unset('LIBRARY_PATH')
+        env.unset('CPATH')
+        env.unset('LD_RUN_PATH')
+        env.unset('DYLD_LIBRARY_PATH')
 
     # Add bin directories from dependencies to the PATH for the build.
     bin_dirs = reversed(
@@ -407,7 +413,7 @@ def load_external_modules(pkg):
             load_module(dep.external_module)
 
 
-def setup_package(pkg):
+def setup_package(pkg, dirty=False):
     """Execute all environment setup routines."""
     spack_env = EnvironmentModifications()
     run_env = EnvironmentModifications()
@@ -430,7 +436,7 @@ def setup_package(pkg):
         s.package.spec = s
 
     set_compiler_environment_variables(pkg, spack_env)
-    set_build_environment_variables(pkg, spack_env)
+    set_build_environment_variables(pkg, spack_env, dirty)
     load_external_modules(pkg)
     # traverse in postorder so package can use vars from its dependencies
     spec = pkg.spec
@@ -459,7 +465,7 @@ def setup_package(pkg):
     spack_env.apply_modifications()
 
 
-def fork(pkg, function):
+def fork(pkg, function, dirty=False):
     """Fork a child process to do part of a spack build.
 
     Arguments:
@@ -467,6 +473,7 @@ def fork(pkg, function):
     pkg -- pkg whose environemnt we should set up the
            forked process for.
     function -- arg-less function to run in the child process.
+    dirty -- If True, do NOT clean the environment before building.
 
     Usage:
        def child_fun():
@@ -490,7 +497,7 @@ def child_fun():
 
     if pid == 0:
         # Give the child process the package's build environment.
-        setup_package(pkg)
+        setup_package(pkg, dirty=dirty)
 
         try:
             # call the forked function.

lib/spack/spack/cmd/install.py

@@ -53,6 +53,9 @@ def setup_parser(subparser):
     subparser.add_argument(
         '--fake', action='store_true', dest='fake',
         help="Fake install.  Just remove the prefix and touch a fake file in it.")
+    subparser.add_argument(
+        '--dirty', action='store_true', dest='dirty',
+        help="Install a package *without* cleaning the environment.")
     subparser.add_argument(
         'packages', nargs=argparse.REMAINDER, help="specs of packages to install")
 
@@ -79,4 +82,5 @@ def install(parser, args):
                 make_jobs=args.jobs,
                 verbose=args.verbose,
                 fake=args.fake,
+                dirty=args.dirty,
                 explicit=True)

lib/spack/spack/package.py

@@ -883,6 +883,7 @@ def do_install(self,
                    make_jobs=None,
                    fake=False,
                    explicit=False,
+                   dirty=False,
                    install_phases = install_phases):
         """Called by commands to install a package and its dependencies.
 
@@ -899,6 +900,7 @@ def do_install(self,
         fake        -- Don't really build -- install fake stub files instead.
         skip_patch  -- Skip patch stage of build if True.
         verbose     -- Display verbose build output (by default, suppresses it)
+        dirty       -- Don't clean the build environment before installing.
         make_jobs   -- Number of make jobs to use for install. Default is ncpus
         """
         if not self.spec.concrete:
@@ -1037,7 +1039,7 @@ def build_process():
                 pass
 
         try:
-            spack.build_environment.fork(self, build_process)
+            spack.build_environment.fork(self, build_process, dirty=dirty)
         except:
             # remove the install prefix if anything went wrong during install.
             if not keep_prefix: