Singularity flags bugfix. (mlcommons#353)

This commit fixes bug that prevents singularity runner to form the correct command line to run singularity-based mlcubes. Concretely, singularity runner now correctly processes command line arguments that requrie values (such as `--security`) and those that do not (flags such as `--nv`).

runners/mlcube_singularity/mlcube_singularity/singularity_run.py

@@ -186,12 +186,17 @@ class SingularityRun(Runner):
  def _get_extra_args(self) -> str:
  """Temporary solution to take into account run arguments provided by users."""
  # Collect all parameters that start with '--' and have a non-None value.
- extra_args = [
- f"{key}={value}"
- for key, value in self.mlcube.runner.items()
- if key.startswith("--") and value is not None and key != "--mount_opts"
- ]
- return " ".join(extra_args)
+ flags = {"--nv"} # These do not require value.
+ ignored = {"--mount_opts"} # Ignore these arguments.
+
+ extra_args: t.List[str] = []
+ for key, value in self.mlcube.runner.items():
+ if key.startswith("--") and value is not None and key not in ignored:
+ extra_args.append(key if key in flags else f"{key}={value}")
+
+ extra_args_as_str = " ".join(extra_args)
+ logger.debug("SingularityRun._get_extra_args extra_args='%s'.", extra_args_as_str)
+ return extra_args_as_str
 
  def __init__(
  self, mlcube: t.Union[DictConfig, t.Dict], task: t.Optional[str]