Fix directory context for git wrap check

authors.txt

@@ -66,3 +66,4 @@ Dima Krasner
 Fabio Porcedda
 Rodrigo Lourenço
 Sebastian Stang
+Marc Becker

mesonbuild/wrap/wrap.py

@@ -129,7 +129,7 @@ class Resolver:
         is_there = os.path.isdir(checkoutdir)
         if is_there:
             try:
-                subprocess.check_call(['git', 'rev-parse'])
+                subprocess.check_call(['git', 'rev-parse'], cwd=checkoutdir)
                 is_there = True
             except subprocess.CalledProcessError:
                 raise RuntimeError('%s is not empty but is not a valid '