ValueError when target name contains a .

[reiyw]

The BazelContainer documentation uses image.tar as an example target name, which actually returns a ValueError.

Traceback

Traceback (most recent call last):
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/.venv/bin/xmanager", line 33, in <module>
    sys.exit(load_entry_point('xmanager', 'console_scripts', 'xmanager')())
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/cli/cli.py", line 65, in entrypoint
    app.run(main)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/.venv/lib/python3.9/site-packages/absl/app.py", line 312, in run
    _run_main(main, args)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/.venv/lib/python3.9/site-packages/absl/app.py", line 258, in _run_main
    sys.exit(main(argv))
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/cli/cli.py", line 41, in main
    app.run(m.main, argv=argv)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/.venv/lib/python3.9/site-packages/absl/app.py", line 312, in run
    _run_main(main, args)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/.venv/lib/python3.9/site-packages/absl/app.py", line 258, in _run_main
    sys.exit(main(argv))
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/launcher.py", line 7, in main
    [executable] = experiment.package(
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm/core.py", line 636, in package
    return cls._async_packager.package(packageables)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm/async_packager.py", line 114, in package
    executables = self._package_batch(packageables)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm_local/packaging/router.py", line 112, in package
    bazel_kinds = bazel_service.fetch_kinds(bazel_labels)
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm_local/packaging/bazel_tools.py", line 186, in fetch_kinds
    labels = [_assemble_label(_lex_label(label)) for label in labels]
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm_local/packaging/bazel_tools.py", line 186, in <listcomp>
    labels = [_assemble_label(_lex_label(label)) for label in labels]
  File "/Users/ryo.takahashi/ghq/github.com/deepmind/xmanager/xmanager/xm_local/packaging/bazel_tools.py", line 160, in _lex_label
    raise ValueError(f'{label} is not an absolute Bazel label')
ValueError: //path/to/target:label.tar is not an absolute Bazel label

This error is caused by _LABEL_LEXER. This regex does not allow the inclusion of a single . which is not an expansion, so the label name in the example will not match.
https://github.com/deepmind/xmanager/blob/18652570332e284a6b2c184e6ab943ca56f6a11a/xmanager/xm_local/packaging/bazel_tools.py#L149-L152

The immediate solution that comes to mind is to allow containing . in the regex, then look for a consecutive . in post-processing like the following:

diff --git a/xmanager/xm_local/packaging/bazel_tools.py b/xmanager/xm_local/packaging/bazel_tools.py
index 694f001..4dc52b0 100644
--- a/xmanager/xm_local/packaging/bazel_tools.py
+++ b/xmanager/xm_local/packaging/bazel_tools.py
@@ -147,7 +147,7 @@ def _build_multiple_targets(
 
 
 # Expansions (`...`, `*`) are not allowed.
-_NAME_RE = '[^:/.*]+'
+_NAME_RE = '[^:/*]+'
 _LABEL_LEXER = re.compile(
     f'^//(?P<packages>{_NAME_RE}(/{_NAME_RE})*)?(?P<target>:{_NAME_RE})?$')
 _LexedLabel = Tuple[List[str], str]
@@ -156,8 +156,10 @@ _LexedLabel = Tuple[List[str], str]
 def _lex_label(label: str) -> _LexedLabel:
   """Splits the label into packages and target."""
   match = _LABEL_LEXER.match(label)
-  if match is None:
-    raise ValueError(f'{label} is not an absolute Bazel label')
+  for g in match.groups('packages'):
+    print('group:', g)
+    if '..' in g:
+      raise ValueError(f'{label} is not an absolute Bazel label')
   groups = match.groupdict()
   packages: Optional[str] = groups['packages']
   target: Optional[str] = groups['target']

[dubov94]

Hi Ryo,

Thanks for flagging!

I'm not a member of the team that builds XManager anymore, but as the author of that problem I'm willing to fix it nevertheless 🙂

In the meantime it can be avoided with Bazel's alias.