Prevent unnecessary submodule fetches

Signed-off-by: Bence Szépkúti <[email protected]>

scripts/abi_check.py

@@ -204,6 +204,19 @@ class AbiChecker:
             stderr=subprocess.STDOUT
         )
         self.log.debug(submodule_output.decode("utf-8"))
+
+        try:
+            # Try to update the submodules using local commits
+            # (Git will sometimes insist on fetching the remote without --no-fetch if the submodules are shallow clones)
+            update_output = subprocess.check_output(
+                [self.git_command, "submodule", "update", "--init", '--recursive', '--no-fetch'],
+                cwd=git_worktree_path,
+                stderr=subprocess.STDOUT
+            )
+        except subprocess.CalledProcessError as err:
+            self.log.debug(err.stdout.decode("utf-8"))
+
+            # Checkout with --no-fetch failed, falling back to fetching from origin
             update_output = subprocess.check_output(
                 [self.git_command, "submodule", "update", "--init", '--recursive'],
                 cwd=git_worktree_path,