Make build-many-glibcs.py clean git source directories.

With the git checkouts of Hurd components in build-many-glibcs.py
involving running autoreconf, there's a risk that generated files
could be left behind by an old autoreconf run (if an old version of
the sources generates those files in the source directory but a new
version does not).

This patch avoids that by using git clean -dxfq when updating git
checkouts.  In this patch, that's conditional on --replace-sources, to
avoid removing any local not-checked-in files someone may have in
their checkout unless the option has been specifically passed that
says it's OK to blow old checkouts away, complete with any local
changes to them.

	* scripts/build-many-glibcs.py (Context.git_checkout): Use git
	clean -dxfq for git updates when replacing sources.

1 files changed, 3 insertions, 0 deletions

diff --git a/scripts/build-many-glibcs.py b/scripts/build-many-glibcs.py
index 0c2ea85b5f..baa6704958 100755
--- a/scripts/build-many-glibcs.py
+++ b/scripts/build-many-glibcs.py
@@ -816,6 +816,9 @@ class Context(object):
         if update:
             subprocess.run(['git', 'remote', 'prune', 'origin'],
                            cwd=self.component_srcdir(component), check=True)
+            if self.replace_sources:
+                subprocess.run(['git', 'clean', '-dxfq'],
+                               cwd=self.component_srcdir(component), check=True)
             subprocess.run(['git', 'pull', '-q'],
                            cwd=self.component_srcdir(component), check=True)
         else: