[OE-core][PATCH] lib/oe/reproducible.py: Fix git HEAD check

["Joshua Watt" <JPEWhacker@gmail.com>]

The check for a git HEAD still wasn't quite correct because it was using
the .git directory as the current working directory. Instead, it should
be passed as the --git-dir argument when running git. Running `git
rev-parse HEAD` in a .git directory with no HEAD reports 'HEAD' and
exits with success but then 'git log' will fail, which is not what we
want.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 meta/lib/oe/reproducible.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/meta/lib/oe/reproducible.py b/meta/lib/oe/reproducible.py
index f4f58dd952..421bb12f54 100644
--- a/meta/lib/oe/reproducible.py
+++ b/meta/lib/oe/reproducible.py
@@ -56,13 +56,13 @@ def get_source_date_epoch_from_git(d, sourcedir):
 
     # Check that the repository has a valid HEAD; it may not if subdir is used
     # in SRC_URI
-    p = subprocess.run(['git', 'rev-parse', 'HEAD'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=gitpath)
+    p = subprocess.run(['git', '--git-dir', gitpath, 'rev-parse', 'HEAD'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     if p.returncode != 0:
         bb.debug(1, "%s does not have a valid HEAD: %s" % (gitpath, p.stdout.decode('utf-8')))
         return None
 
     bb.debug(1, "git repository: %s" % gitpath)
-    p = subprocess.run(['git','log','-1','--pretty=%ct'], check=True, stdout=subprocess.PIPE, cwd=gitpath)
+    p = subprocess.run(['git', '--git-dir', gitpath, 'log', '-1', '--pretty=%ct'], check=True, stdout=subprocess.PIPE)
     return int(p.stdout.decode('utf-8'))
 
 def get_source_date_epoch_from_youngest_file(d, sourcedir):
-- 
2.27.0