Fix rc init when matplotlib is imported first - #569
Merged
Conversation
K-Mirembe-Mercy
pushed a commit
to K-Mirembe-Mercy/UltraPlot
that referenced
this pull request
Mar 22, 2026
* Fix rc init when matplotlib is imported first
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
This fixes issue #568 where importing matplotlib.pyplot before ultraplot could make rc initialization fail with axes.titlesize set to med-large validation errors. The root cause was font-size validator patching that relied on validator object identity, which is not stable across Matplotlib builds; this patch adds behavior-based detection so relevant size validators are consistently routed through UltraPlot custom fontsize validation. It also expands subprocess regression coverage in test_config.py to enforce the problematic import order and verify both general rc mutation and med-large assignments across multiple font-size keys.