Merge pull request #1217 from LLNL/features/git-submodule-init

Add `submodules` option for git fetching.

lib/spack/docs/packaging_guide.rst

@@ -604,6 +604,7 @@ Git fetching is enabled with the following parameters to ``version``:
   * ``tag``: name of a tag to fetch.
   * ``branch``: name of a branch to fetch.
   * ``commit``: SHA hash (or prefix) of a commit to fetch.
+  * ``submodules``: Also fetch submodules when checking out this repository.
 
 Only one of ``tag``, ``branch``, or ``commit`` can be used at a time.
 
@@ -660,6 +661,17 @@ Commits
   could just use the abbreviated commit hash.  It's up to the package
   author to decide what makes the most sense.
 
+Submodules
+
+  You can supply ``submodules=True`` to cause Spack to fetch submodules
+  along with the repository at fetch time.
+
+  .. code-block:: python
+
+     version('1.0.1', git='https://github.com/example-project/example.git',
+             tag='v1.0.1', submdoules=True)
+
+
 Installing
 ^^^^^^^^^^^^^^
 

lib/spack/spack/fetch_strategy.py

@@ -366,8 +366,8 @@ def fetch(self):
             try:
                 self.check()
             except ChecksumError:
-                # Future fetchers will assume they don't need to download if the
-                # file remains
+                # Future fetchers will assume they don't need to
+                # download if the file remains
                 os.remove(self.archive_file)
                 raise
 
@@ -517,6 +517,7 @@ def __init__(self, **kwargs):
         super(GitFetchStrategy, self).__init__(
             'git', 'tag', 'branch', 'commit', **forwarded_args)
         self._git = None
+        self.submodules = kwargs.get('submodules', False)
 
     @property
     def git_version(self):
@@ -595,6 +596,10 @@ def fetch(self):
                 self.git('pull', '--tags', ignore_errors=1)
                 self.git('checkout', self.tag)
 
+        # Init submodules if the user asked for them.
+        if self.submodules:
+            self.git('submodule', 'update', '--init')
+
     def archive(self, destination):
         super(GitFetchStrategy, self).archive(destination, exclude='.git')