Summary

v4.2.1 breaks pnpm resolution via mise shims in subsequent workflow steps.

Environment

• jdx/mise-action@v4.2.1 (sha dad1bfd3df957f44999b559dd69dc1671cb4e9ea)
• ubuntu-24.04 GitHub-hosted runner
• mise 2026.7.7 (installed by the action)
• mise.toml pins pnpm = "11.9.0" (installed via the built-in npm backend)

Reproduction

Any workflow that installs pnpm via mise.toml and then invokes pnpm in a later step:

- uses: jdx/mise-action@v4.2.1
- run: pnpm install --frozen-lockfile

Actual

mise ERROR pnpm is not a valid shim. This likely means you uninstalled
a tool and the shim does not point to anything. Run `mise use <TOOL>`
to reinstall the tool.
Error: Process completed with exit code 1.

Downgrading to v4.2.0 (e6a8b3978addb5a52f2b4cd9d91eafa7f0ab959d) fixes it.

Suspected cause

v4.2.0...v4.2.1 includes PR #556 ("fix: exclude PATH from environment
export", closes #555). That PR redacts PATH modifications from the
env-export step. mise activate installs pnpm as a shim under
$MISE_INSTALLS_DIR/pnpm/*/ and prepends that directory to PATH; if
the redaction strips those shim PATH entries, pnpm becomes unresolvable
in later steps — which is the observed failure.

The intended fix in #556 (not leaking user PATH from inputs.env) seems
right, but the current implementation looks like it also drops the shim
PATH entries the action itself installed.

Failing CI runs

• kaelys-js/kaelys-js@PR#15 run https://github.com/kaelys-js/kaelys-js/actions/runs/29712727330/job/88259373436
• kaelys-js/kaelys-js-infra@PR#56 (same shape)

Workaround

Pin <4.2.1 via renovate allowedVersions.