Fix for `git pull --tags` when using git 1.7.1

- Added `ignore_errors` option to `Executable.__call__`
- Can avoid raising errors on *specific* error return values.

2 files changed, 11 insertions, 2 deletions

diff --git a/lib/spack/spack/fetch_strategy.py b/lib/spack/spack/fetch_strategy.py
index 3e6f59d9b8..0ba0251caa 100644
--- a/lib/spack/spack/fetch_strategy.py
+++ b/lib/spack/spack/fetch_strategy.py
@@ -437,7 +437,10 @@ class GitFetchStrategy(VCSFetchStrategy):
             # cloning.  Later git versions can do this with clone
             # --branch, but older ones fail.
             if self.tag and self.git_version < ver('1.8.5.2'):
-                self.git('pull', '--tags')
+                # pull --tags returns a "special" error code of 1 in
+                # older versions that we have to ignore.
+                # see: https://github.com/git/git/commit/19d122b
+                self.git('pull', '--tags', ignore_errors=1)
                 self.git('checkout', self.tag)
 
 
diff --git a/lib/spack/spack/util/executable.py b/lib/spack/spack/util/executable.py
index 1dcda0d87f..67e8cddd98 100644
--- a/lib/spack/spack/util/executable.py
+++ b/lib/spack/spack/util/executable.py
@@ -57,8 +57,13 @@ class Executable(object):
         """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)
+        ignore_errors = kwargs.get("ignore_errors", ())
         error         = kwargs.get("error", sys.stderr)
 
+        # if they just want to ignore one error code, make it a tuple.
+        if isinstance(ignore_errors, int):
+            ignore_errors = (ignore_errors,)
+
         quoted_args = [arg for arg in args if re.search(r'^"|^\'|"$|\'$', arg)]
         if quoted_args:
             tty.warn("Quotes in command arguments can confuse scripts like configure.",
@@ -85,7 +90,8 @@ class Executable(object):
             out, err = proc.communicate()
             self.returncode = proc.returncode
 
-            if fail_on_error and proc.returncode != 0:
+            rc = proc.returncode
+            if fail_on_error and rc != 0 and (rc not in ignore_errors):
                 raise ProcessError("Command exited with status %d:"
                                    % proc.returncode, cmd_line)
             if return_output: