Fix loader handling of sys.modules #68284
Open
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
0614391 to
e056c81
Compare
Commit e579012 migrated away from the deprecated `load_module` to `exec_module`. The latter does not reload modules like the deprecated function. Since the loader assumes modules in `sys.modules` are never replaced, but reloaded, ensure that's the case. There are likely better solutions in theory, but this commit quickly reverts to the legacy behavior the loader is used to. If we replace modules instead, a mismatch between the cached functions in a LazyLoader instance and the ones found on modules in `sys.modules` can develop when we instantiate nested loaders of the same type and load the same module with both.
e056c81 to
776c3fc
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What does this PR do?
Makes the LazyLoader reload already loaded modules instead of replacing them.
What issues does this PR fix or reference?
Fixes: #68281
Previous Behavior
Since e579012 (#65032), a new loader always created new modules and overwrote existing ones in
sys.modules.This could cause unexpected behavior because parts of the loader code assumed that a cached function in their
_dictalways belongs to the corresponding module insys.modules(details: #68281 (comment))New Behavior
Modules are reloaded instead of replaced when possible, which aligns with the behavior in 3006.x (I think, please feel free to correct me and let's see what the test suite says).
Merge requirements satisfied?
Commits signed with GPG?
Yes