External dependencies & JLLs

Agent Skill metadata

name: external-deps
description: Modify Julia's external dependencies and JLLs — patches under deps/patches/, version bumps in deps/, and JLL updates. Use when touching deps/ or any *_jll folder, including refreshing checksums.

Use this when modifying deps/, dependency patches, or a JLL.

External dependencies (deps/, deps/patches/)

When modifying external dependencies (patches in deps/patches/ or version updates in deps/):

Always test builds with USE_BINARYBUILDER=0 to ensure source builds work correctly.
For patches to external libraries:
- Verify the patch applies cleanly by running the extraction and patch steps.
- Test the full build of the dependency: make -C deps USE_BINARYBUILDER=0 compile-<depname>.
- Prefer using the full upstream commit in git am format (e.g., git format-patch) which includes proper commit metadata.
When updating dependency versions, ensure all associated patches still apply.

To update a JLL to the latest version:

Update the version number in the appropriate jll folder.
If the dependencies in the upstream jll changed, update the Project.toml.
Run make -f contrib/refresh_checksums.mk <jll> to update the checksums. This may take a few minutes.