Skill v1.0.0

version: "1.0.0" description: Update a Julia package's [compat] to allow a new breaking version of a dependency, then fix whatever the upgrade breaks. Use when the user says a dependency has a new major/breaking release, asks to "bump compat", "allow version X of Y", or a CompatHelper PR needs finishing by hand.

Update the package in the current directory to allow a new breaking version of a dependency. The dependency name and new version should be specified by the user; ask if not provided.

Two kinds of Julia invocation are used here, for different reasons. One-shot julia --project -e ... processes give clean, reproducible results for the baseline and final test runs and for Pkg operations. The iterative fix loop uses the MCP Julia session so that Revise amortizes compilation across attempts; do not load Revise in a one-shot process, where it has nothing to track.

1. Verify baseline

Run the test suite in a fresh process and confirm everything passes before making any changes:

julia --project -e 'using TestEnv; TestEnv.activate(); include("test/runtests.jl")'

Do not proceed if any tests fail: the upgrade's breakage cannot be distinguished from pre-existing failures. Report the failures to the user and stop.

2. Bump [compat]

In Project.toml, update the [compat] entry for the dependency to include the new version. Preserve the existing lower bound unless the user instructs otherwise.

3. Update and verify resolver selection

julia --project -e 'using Pkg; Pkg.update("<dependency>")'
julia --project -e 'using Pkg; Pkg.status("<dependency>")'

If the resolver did not select the new version, stop and report: another [compat] entry or an indirect dependency is constraining it, and guessing at fixes hides the real conflict.

4. Fix breakage

Start (or reuse) an MCP Julia session with env_path pointing at the package's Project.toml, then:

using TestEnv; TestEnv.activate()
include("test/runtests.jl")

Diagnose failures and edit src/; Revise applies the edits, so re-running include("test/runtests.jl") in the same session picks them up without recompiling the package. Read the dependency's release notes or changelog for the breaking version when the cause is not obvious from the error.

5. Confirm and commit

Run the fresh-process test command from step 1 once more; the persistent session can mask ordering or stale-state problems that a clean process exposes.

Commit the compat bump and any fixes together, with a message that names the dependency and the version range now allowed.