Draft: import-debian-package: stop using a PosixPath object as context manager

tools/apertis-pkg-merge-upstream-to-downstreams

@@ -183,6 +183,32 @@ def ensure_downstream_branch(project_url, downstream, dry_run):
         raise
 
 
+def get_path_with_namespace(project_url):
+    url = urllib.parse.urlsplit(project_url)
+    project_id = urllib.parse.quote(removesuffix(url.path.strip("/"), ".git"), safe="")
+    # drop the inline auth data as urllib does not like it
+    auth, netloc_no_auth = url.netloc.split("@", 1)
+    token = auth.split(":", 1)[-1]
+    url = url._replace(
+        path=f"/api/v4/projects/{project_id}",
+        netloc=netloc_no_auth,
+    )
+    project_metadata = url.geturl()
+    req_project_metadata = urllib.request.Request(
+        url=project_metadata,
+        headers={"PRIVATE-TOKEN": token},
+    )
+    try:
+        res = urllib.request.urlopen(req_project_metadata)
+        json_res = json.load(res)
+        path_with_namespace = json_res["path_with_namespace"]
+    except urllib.error.HTTPError as e:
+        print("ERROR:", e.read().decode())
+        raise
+
+    return path_with_namespace
+
+
 def push_merge_request(
     project_url, proposed_branch, upstream, downstream, auto_merge="", dry_run=False
 ):
@@ -213,8 +239,11 @@ def push_merge_request(
 
     ensure_downstream_branch(project_url, downstream, dry_run)
 
+    project_path = get_path_with_namespace(project_url)
+
     print(
-        f"Create merge request from '{proposed_branch}' to '{downstream}'", flush=True
+        f"Create merge request from '{proposed_branch}' to '{project_path}/{downstream}'",
+        flush=True,
     )
     git_push_custom(
         "-o",
@@ -224,6 +253,8 @@ def push_merge_request(
         "-o",
         f"merge_request.target={downstream}",
         "-o",
+        f"merge_request.target_project={project_path}",
+        "-o",
         f"merge_request.title={title}",
         project_url,
         f"{proposed_branch}:{proposed_branch}",