aosabook/500lines · error · Exception

Could not update and check repository. Reason: %s

Error message

Could not update and check repository. Reason: %s

What it means

Error "Could not update and check repository. Reason: %s" thrown in aosabook/500lines.

Source

Thrown at ci/code/repo_observer.py:38

def poll():
    parser = argparse.ArgumentParser()
    parser.add_argument("--dispatcher-server",
                        help="dispatcher host:port, " \
                        "by default it uses localhost:8888",
                        default="localhost:8888",
                        action="store")
    parser.add_argument("repo", metavar="REPO", type=str,
                        help="path to the repository this will observe")
    args = parser.parse_args()
    dispatcher_host, dispatcher_port = args.dispatcher_server.split(":")
    while True:
        try:
            # call the bash script that will update the repo and check
            # for changes. If there's a change, it will drop a .commit_id file
            # with the latest commit in the current working directory
            subprocess.check_output(["./update_repo.sh", args.repo])
        except subprocess.CalledProcessError as e:
            raise Exception("Could not update and check repository. Reason: %s" % e.output)

        if os.path.isfile(".commit_id"):
            # great, we have a change! let's execute the tests
            # First, check the status of the dispatcher server to see
            # if we can send the tests
            try:
                response = helpers.communicate(dispatcher_host,
                                               int(dispatcher_port),
                                               "status")
            except socket.error as e:
                raise Exception("Could not communicate with dispatcher server: %s" % e)
            if response == "OK":
                # Dispatcher is present, let's send it a test
                commit = ""
                with open(".commit_id", "r") as f:
                    commit = f.readline()
                response = helpers.communicate(dispatcher_host,
                                               int(dispatcher_port),

View on GitHub (pinned to fba689d101)

Solutions

1. Verify the repository path passed to repo_observer is correct and accessible.
2. Run ./update_repo.sh manually against the repo to see the underlying failure (permissions, git errors, network).
3. Ensure the observer process has read/write permissions to the repository and its working directory.

Example fix

./update_repo.sh /path/to/repo  # inspect its error output, then fix the reported git/permission issue before restarting the observer

When it happens

Trigger: Thrown at ci/code/repo_observer.py:38 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of aosabook/500lines@fba689d101 (2026-08-13). Data as JSON: /api/errors/f3cf5fc76a7eb143. Report an issue: GitHub.