bazelbuild/bazel · error · ValueError

Could not get config: {stderr}

Error message

Could not get config: {stderr}

What it means

Thrown by tools/ctexplain's bazel_api.get_config() when 'bazel config --output=json <hash>' exits non-zero. ctexplain resolves each configuration hash from cquery output into a full Configuration via this call; failure to fetch the config aborts with the raw bazel stderr attached.

Source

Thrown at tools/ctexplain/bazel_api.py:114

    Args:
      config_hash: A config hash as reported by "bazel cquery".

    Returns:
      The matching configuration or None if no match is found.

    Raises:
      ValueError: On any parsing problems.
    """
    if config_hash == "HOST":
      return HostConfiguration()
    elif config_hash == "null":
      return NullConfiguration()

    base_args = ["config", "--output=json"]
    (returncode, stdout, stderr) = self.run_bazel(base_args + [config_hash])
    if returncode != 0:
      raise ValueError("Could not get config: " + stderr)
    config_json = json.loads(os.linesep.join(stdout))
    fragments = frozendict({
        _base_name(entry["name"]):
        tuple(_base_name(clazz) for clazz in entry["fragmentOptions"])
        for entry in config_json["fragments"]
    })
    options = frozendict({
        _base_name(entry["name"]): frozendict(entry["options"])
        for entry in config_json["fragmentOptions"]
    })
    return Configuration(fragments, options)


# TODO(gregce): have cquery --output=jsonproto support --show_config_fragments
# so we can replace all this regex parsing with JSON reads.
def _parse_cquery_result_line(line: str) -> ConfiguredTarget:
  """Converts a cquery output line to a ConfiguredTarget.

View on GitHub (pinned to e6e199d060)

Solutions

1. Run 'bazel config <hash>' manually with the same output base to see the underlying bazel error shown in stderr.
2. Regenerate the cquery data you are diffing in the same workspace state so hashes exist in the current server.
3. Restart/shut down the bazel server ('bazel shutdown') if a version or workspace change invalidated it, then retry.

rc, out, err = run_bazel(['config', '--output=json', config_hash])
if rc != 0:
    raise ValueError('config %s unknown to server: %s' % (config_hash, err))

try:
    config = bazel.get_config(ct.config_hash)
except ValueError as e:
    # 'Could not get config: ...' — regenerate cquery data in this workspace
    raise

When it happens

Trigger: Passing a config hash that the current bazel server does not know (from a stale cquery dump or a different output base), the bazel server being shut down mid-run, or bazel itself erroring (e.g. workspace problems) during 'bazel config'.

Common situations: Comparing cquery output captured before a 'bazel clean' or server restart; running ctexplain in a workspace where bazel needs a restart (version change); config hash from another invocation directory.

Related errors

• {tokens[1]} in {line} not surrounded by parentheses
• {tokens[2]} in {line} not surrounded by [] brackets
• invocation failed: {stderr}
• Could not create custom sharding strategy class ${strategy}
• Unsupported JUnit Runner API version ${JUNIT_API_VERSION_PRO

AI-assisted analysis of bazelbuild/bazel@e6e199d060 (2026-08-14). Data as JSON: /api/errors/0d2aaa789770ec92. Report an issue: GitHub.