[Bug] Hydra resolver does not work in compose_api

🐛 Bug

Description

hydra:key substitution does not work in interactive Python session and Jupyter notebook. hydra.key does, but it is not recommended (according to https://github.com/facebookresearch/hydra/issues/1786#issuecomment-914734857).

Checklist

• I checked on the latest version of Hydra
• I created a minimal repro (See this for tips).

To reproduce

** Minimal Code/Config snippet to reproduce **

conf/config.yaml

defaults:
  - env: dev

conf/env/prod.yaml

spark:
    appName: ${hydra:job.name}

conf/env/dev.yaml

spark:
    appName: ${hydra.job.name}

run.py

from hydra import initialize, compose

with initialize(config_path="conf"):
    conf = compose(config_name="config.yaml", return_hydra_config=True)
    print(conf.env.spark.appName)
    # prints current file name, e.g. "run"

with initialize(config_path="conf"):
    conf = compose(config_name="config.yaml", return_hydra_config=True, overrides=["env=prod"])
    print(conf.env.spark.appName)
    # raises exception

** Stack trace/error message **

$ python run.py
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/dictconfig.py", line 357, in __getattr__
    self._format_and_raise(key=key, value=None, cause=e)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 196, in _format_and_raise
    type_override=type_override,
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/_utils.py", line 821, in format_and_raise
    _raise(ex, cause)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/_utils.py", line 719, in _raise
    raise ex.with_traceback(sys.exc_info()[2])  # set end OC_CAUSE=1 for full backtrace
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/dictconfig.py", line 351, in __getattr__
    return self._get_impl(key=key, default_value=_DEFAULT_MARKER_)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/dictconfig.py", line 446, in _get_impl
    key=key, value=node, default_value=default_value
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/basecontainer.py", line 69, in _resolve_with_default
    throw_on_resolution_failure=True,
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 622, in _maybe_resolve_interpolation
    memo=memo if memo is not None else set(),
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 483, in _resolve_interpolation_from_parse_tree
    parse_tree=parse_tree, node=value, key=key, parent=parent, memo=memo
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 669, in resolve_parse_tree
    ).with_traceback(sys.exc_info()[2])
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 662, in resolve_parse_tree
    return visitor.visit(parse_tree)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/antlr4/tree/Tree.py", line 34, in visit
    return tree.accept(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar/gen/OmegaConfGrammarParser.py", line 205, in accept
    return visitor.visitConfigValue(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar_visitor.py", line 101, in visitConfigValue
    return self.visit(ctx.getChild(0))
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/antlr4/tree/Tree.py", line 34, in visit
    return tree.accept(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar/gen/OmegaConfGrammarParser.py", line 339, in accept
    return visitor.visitText(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar_visitor.py", line 298, in visitText
    return self.visitInterpolation(c)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar_visitor.py", line 125, in visitInterpolation
    return self.visit(ctx.getChild(0))
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/antlr4/tree/Tree.py", line 34, in visit
    return tree.accept(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar/gen/OmegaConfGrammarParser.py", line 1030, in accept
    return visitor.visitInterpolationResolver(self)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/grammar_visitor.py", line 182, in visitInterpolationResolver
    args_str=tuple(args_str),
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 653, in resolver_interpolation_callback
    inter_args_str=args_str,
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/base.py", line 596, in _evaluate_custom_resolver
    inter_args_str,
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/omegaconf/omegaconf.py", line 435, in resolver_wrapper
    ret = resolver(*args, **kwargs)
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/hydra/core/utils.py", line 215, in <lambda>
    lambda path: OmegaConf.select(cast(DictConfig, HydraConfig.get()), path),
  File "/home/maxim/Repo/ds-demo-project/venv/lib/python3.7/site-packages/hydra/core/hydra_config.py", line 31, in get
    raise ValueError("HydraConfig was not set")
omegaconf.errors.InterpolationResolutionError: ValueError raised while resolving interpolation: HydraConfig was not set
    full_key: env.spark.appName
    object_type=dict

Expected Behavior

Substitutionshydra: are not causing an exception inside a context created by compose function with return_hydra_config=True. HydraConfig instance should be initialized.

System information

• Hydra Version : both 1.1.0 from pypi and 2a9f181 commit from main branch
• Python version : both 3.7.8 and 3.10.2
• Virtual environment type and version : venv
• Operating system : Linux x86_64 5.16.5-1

Additional context

Same behavior has been observed several times: #716 https://github.com/facebookresearch/hydra/issues/1786#issuecomment-913110496

[Jasha10]

Yes indeed, the ConfigStore is persistent global state.

For Hydra’s test suite, we have a hydra_restore_singletons fixture that is used to save and then later restore the global state so that the tests can be run independently.

[Jasha10]

Thanks for looking into this @odelalleau! I’ll try to put together an implementation for compose_context.

I’m thinking that a usage pattern involving OmegaConf.resolve could even make the cfg object behave nicely after the context has ended:

with initialize(...):
    with compose_context(...) as cfg:
        OmegaConf.resolve(cfg)  # makes cfg usable outside of the context
...
application_logic(cfg.foo)