From cdc2ebee9018cc4cf067d73f269628901a8d4487 Mon Sep 17 00:00:00 2001
From: Todd Gamblin <tgamblin@llnl.gov>
Date: Mon, 18 Jul 2016 01:11:24 -0700
Subject: [PATCH] Better error messages for `spack reindex`.

---
 lib/spack/spack/database.py         |  7 ++++---
 lib/spack/spack/directory_layout.py | 17 +++++++++++++----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
index c95abd7423..eabf740dbc 100644
--- a/lib/spack/spack/database.py
+++ b/lib/spack/spack/database.py
@@ -646,6 +646,7 @@ def __init__(self, path, msg=''):
 class InvalidDatabaseVersionError(SpackError):
     def __init__(self, expected, found):
         super(InvalidDatabaseVersionError, self).__init__(
-            "Expected database version %s but found version %s." + \
-            "Try running `spack reindex` to fix." %
-            (expected, found))
+            "Expected database version %s but found version %s."
+            % (expected, found),
+            "`spack reindex` may fix this, or you may need a newer "
+            "Spack version.")
diff --git a/lib/spack/spack/directory_layout.py b/lib/spack/spack/directory_layout.py
index a5e76043ad..8150a6da2b 100644
--- a/lib/spack/spack/directory_layout.py
+++ b/lib/spack/spack/directory_layout.py
@@ -34,6 +34,7 @@
 import llnl.util.tty as tty
 from llnl.util.filesystem import join_path, mkdirp
 
+import spack
 from spack.spec import Spec
 from spack.error import SpackError
 
@@ -223,8 +224,14 @@ def write_spec(self, spec, path):
 
     def read_spec(self, path):
         """Read the contents of a file and parse them as a spec"""
-        with open(path) as f:
-            spec = Spec.from_yaml(f)
+        try:
+            with open(path) as f:
+                spec = Spec.from_yaml(f)
+        except Exception as e:
+            if spack.debug:
+                raise
+            raise SpecReadError(
+                'Unable to read file: %s' % path, 'Cause: ' + str(e))
 
         # Specs read from actual installations are always concrete
         spec._mark_concrete()
@@ -456,10 +463,12 @@ def __init__(self, path):
             "Install path %s already exists!")
 
 
+class SpecReadError(DirectoryLayoutError):
+    """Raised when directory layout can't read a spec."""
+
+
 class InvalidExtensionSpecError(DirectoryLayoutError):
     """Raised when an extension file has a bad spec in it."""
-    def __init__(self, message):
-        super(InvalidExtensionSpecError, self).__init__(message)
 
 
 class ExtensionAlreadyInstalledError(DirectoryLayoutError):