{"record":{"id":"58d19e7188c0fdd1","repo":"jax-ml/jax","slug":"could-not-find-location-in-string-location-string","errorCode":null,"errorMessage":"Could not find location in string {location_string}","messagePattern":"Could not find location in string (.+?)","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"warning","filePath":"jax/_src/pallas/mosaic/error_handling.py","lineNumber":149,"sourceCode":"  Args:\n    location_string: A string serialization of an MLIR location.\n\n  Returns:\n    A tuple (name, frames) where name is the name of the location and frames\n    is a list of RawFrame objects representing the Python call stack associated\n    with the location.\n  \"\"\"\n  frame_str = ''\n  loc_name = None\n  matches = list(re.finditer(LOCATION_PATTERN, location_string))\n  if len(matches) > 1:\n    raise ValueError(\n        'More than one location found in string: ', location_string)\n  for mat in matches:\n    loc_name = mat.group('eqn_str')[1:-1]\n    frame_str = mat.group('frames')[1:-1]\n  if loc_name is None:\n    raise ValueError(f'Could not find location in string {location_string}')\n  frames: list[RawFrame] = []\n  for mat in re.finditer(FRAME_PATTERN, frame_str):\n    frames.append(\n        RawFrame(\n            mat.group('fun_name')[1:-1],\n            mat.group('filename')[1:-1],\n            int(mat.group('lineno')),\n            int(mat.group('colno')),\n        )\n    )\n  return loc_name, frames\n\n\ndef traceback_from_raw_frames(frames: list[RawFrame]) -> types.TracebackType:\n  \"\"\"Constructs a traceback from a list of RawFrame objects.\"\"\"\n  xla_frames = [\n    xla_client.Frame(frame.filename, frame.func_name, -1, frame.lineno)\n    for frame in frames","sourceCodeStart":131,"sourceCodeEnd":167,"githubUrl":"https://github.com/jax-ml/jax/blob/1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb/jax/_src/pallas/mosaic/error_handling.py#L131-L167","documentation":"The location parser found zero matches for the expected location pattern in the error string, so it cannot recover the equation name and Python frames needed to build a user-facing traceback. This usually means the XLA error format doesn't match what the parser expects.","triggerScenarios":"An XLA runtime error whose message lacks the standard location annotation (e.g., an error emitted before tracing info attached, or from a different M/XLA version) reaching parse_location_string.","commonSituations":"Version mismatch between Mosaic and the XLA runtime producing differently-formatted errors; errors from uninstrumented code paths; out-of-memory or driver-level errors with no source location.","solutions":["Update JAX and libtpu/Mosaic together so error formats match","Look at the raw XLA error text directly for diagnosis — the location metadata is simply missing","Report the raw error string to JAX maintainers if it persists on matched versions"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"try:\n    loc = parse_location_string(err_str)\nexcept ValueError:\n    log.warning('no location in XLA error: %s', err_str)\n    loc = None","preventionTips":["Log raw XLA errors verbatim alongside parsed tracebacks","Don't build tooling that assumes location metadata always exists"],"tags":["jax","pallas","tpu","error-handling","parsing"],"backgroundTag":"error-message-parse-failure","analyzedSha":"1e1c6a8fc06dfcd1247076ec5cae4640cea5d7bb","analyzedAt":"2026-08-27T09:53:25.647Z","schemaVersion":2},"datasetVersion":"2026-08-27T13:17:12.746Z"}