chore: centralize development and CI verbs in just (#4372)

* chore: extract just recipes from hatch replacement proposal

Extracts the Justfile from 98dcde7 (#4096). Environment and CI migration changes are adapted separately.

Assisted-by: Codex:GPT-6

* chore: use just for python helpers

Extracts the Justfile changes from 693f694 (#4096).

Assisted-by: Codex:GPT-6

* chore: centralize development and CI verbs in just

Keep Hatch environment definitions while moving task commands into Justfile. Route root CI, Read the Docs, and contributor workflows through the same recipes, preserve quoted arguments, and ship recipes and helpers in the sdist.

Assisted-by: Codex:GPT-6

* chore: delegate package commands to their justfiles

Expose package recipes from the root while retaining each package’s command definitions and working directory.

Assisted-by: Codex:GPT-6

* fix(ci): harden the just migration's environment, pinning and release path

Review follow-ups to the Justfile centralization:

- `just gpu` read HATCH_ENV, so an exported CPU test environment silently
  redirected `pytest -m gpu` into an env built without the gpu feature. It now
  reads GPU_HATCH_ENV, which nothing else sets.
- Pin `uvx prek` to 0.5.3 and restore hook-environment caching in the lint
  workflow, so lint no longer floats on whatever prek PyPI serves that day.
- Restore the mypy hook's `uv run --frozen mypy` entry: routing it through
  `just typecheck` made just a prerequisite for committing in every existing
  clone, and expanded to the identical command.
- Run the changelog filename check with `uv run --no-project python` instead of
  building the `dev` hatch env (test + remote-tests + docs + mypy) for a script
  that imports only sys and pathlib.
- Extend `just just-check` over packages/*/justfile, which the root delegation
  recipes depend on and the formatting gate did not cover.
- Set up Python in the codspeed job before pip-installing into it, matching the
  other workflows; that runner image was never given one.
- Revert the release and nightly-wheel jobs to `hatch build`, so the publishing
  path does not fetch rust-just to run a pure alias.
- Renumber the changelog fragment to this pull request and credit #4096 in the
  body, so the rendered note does not link to an unrelated upstream PR.

Assisted-by: ClaudeCode:claude-opus-5

* fix(ci): install prek persistently for git hooks; run setup steps in one just process

`just hooks-install` ran `uvx prek install`, and prek writes a hook shim that
hard-codes the binary it was installed from, falling back to `prek` on PATH.
Under uvx that path is an entry in uv's archive cache, so the first
`uv cache prune` (or a bump of the pinned version) broke every commit with
`prek: not found`, and nothing put `prek` on PATH for the fallback. Install it
as a pinned `uv tool` instead: a changed pin upgrades in place, a repeated run
is a no-op, and the shim points at a path that stays.

`setup` re-invoked `just list-env`, which dropped a `just hatch_env=... setup`
override on the floor because the child process re-read HATCH_ENV. Run it as a
subsequent dependency so both steps see the same value.

Also retire the last two comments naming the removed hatch scripts.

Assisted-by: ClaudeCode:claude-fable-5-1

* chore: renumber the changelog fragment to the upstream pull request

towncrier renders the fragment name as a link into
zarr-developers/zarr-python, so the fork's PR number would have pointed the
released note at an unrelated upstream pull request. #4372 is the PR that
merges this work.

Assisted-by: ClaudeCode:claude-opus-5
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* ci: install just as a binary in the benchmark job

Adding `actions/setup-python` to this job so that `pip install rust-just` had
an interpreter also changed which interpreter hatch built
`test.py3.12-minimal` on: the runner's own Python was replaced by
/opt/hostedtoolcache/Python/3.12.5/arm64. CodSpeed measured the result as a
12.97% degradation across 26 benchmarks, spread -12.76% to -13.99% -- a range
of 1.2 points over slice indexing, sharded Morton indexing, three array shapes
and two store types. Nothing in this branch touches src/, tests/benchmarks/ or
packages/; that uniformity is an interpreter swap, not a regression, and
CodSpeed flagged it as "different runtime environments detected".

Install just with extractions/setup-just instead, matching the three package
workflows. No interpreter is set up, so hatch resolves the same Python the
baseline used, and `just-version` is pinned to satisfy zizmor's unpinned-tools
audit.

The benchmarks need a re-run to produce a comparison against a matching
environment; the numbers on the previous run should not be acknowledged as a
regression.

Assisted-by: ClaudeCode:claude-opus-5
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* ci: install just from official release binaries; lock the docs toolchain

Follow-ups from an adversarial audit of this branch.

Supply chain. `rust-just` is a third-party repackaging of just on PyPI
(Repository: github.com/gnpaone/rust-just) with no attestation on any of its
17 wheels, and this branch had introduced it in ten places including the
self-hosted GPU runner and Read the Docs. All 23 just installs across the repo
now come from casey/just's own release binaries via
extractions/setup-crate@7577c1bd (v2.0.1), a node action whose SHA pins every
line of executed code -- rather than extractions/setup-just, a composite
wrapper that astral-sh/python-build-standalone#771 moved off for that reason.
This also retires the 12 pre-existing setup-just call sites, so the repo has
one mechanism instead of four. setup-crate does not verify checksums
(extractions/setup-just#20 is open); Read the Docs, where no action is
available, fetches the release tarball and verifies it against the SHA256SUMS
casey/just publishes.

Lockfile. docs.yml had stopped resolving from uv.lock: `uv sync --group docs`
became `hatch run docs:`, and hatch never reads the lockfile, so the entire
docs toolchain floated -- including numcodecs[msgpack], which carries no
version constraint. Dependabot's uv ecosystem exists to keep that lock fresh
and no job exercised it any more. The eight docs and changelog recipes now run
`uv run --frozen --group docs`, so single-version tooling comes from the lock
(as mypy already did) while hatch keeps the test environments, which exist per
interpreter and per dependency set and cannot live in one lockfile. The hatch
docs environment is removed as unused, and neither docs.yml nor Read the Docs
installs hatch at all now.

Argument forwarding. The three package justfiles splatted `{{ args }}`
unquoted, so `just zarr-metadata test -k 'a and b'` reached pytest as `-k a`
plus two stray paths, and command substitution in an argument executed. They
now use `set positional-arguments` and `"$@"` like the root, which is what the
contributing guide already claimed.

Also, regressions from my own earlier commits on this branch: `just lint` had
dropped `--show-diff-on-failure --color=always`, which j178/prek-action passed
by default, so a hook that rewrote a file failed with no diff; a four-line
comment above `hooks-install` displaced its `just --list` description, since
just reads only the last comment line; the prek cache key did not cover
prek_version and had a restore-keys fallback that could reuse a store built by
a different prek; `just just-check` ran before `just lint`, so a cosmetic
formatting nit hid every real lint result; and the `packages/*/justfile` glob
lacked nullglob, which breaks in the sdist, where /Justfile ships but
/packages deliberately does not.

Docs: the install instructions used `pip install`, which fails on an
externally-managed interpreter; `just just-check` was an undocumented required
check; two sentences still told contributors to activate an environment that
no longer exists; and the changelog fragment did not mention that the Hatch
script tables were removed. Adds a .gitattributes rule so a Windows checkout
does not get a CRLF Justfile that `just --fmt --check` rejects on every line.

Assisted-by: ClaudeCode:claude-opus-5
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Max Jones <14077947+maxrjones@users.noreply.github.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: 3 people

.gitattributes

@@ -1,3 +1,9 @@
 *.py linguist-language=python
 *.ipynb linguist-documentation
 .git_archival.txt export-subst
+
+# just refuses to format a CRLF file, so `just just-check` would fail on a Windows
+# checkout with core.autocrlf=true before the contributor has changed anything.
+Justfile text eol=lf
+*/justfile text eol=lf
+packages/*/justfile text eol=lf

.github/workflows/check_changelogs.yml

@@ -24,14 +24,20 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
 
+      - name: Install just
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+        with:
+          repo: casey/just
+          version: 1.58.0
+
       - name: Check zarr-python changelog entries
-        run: uv run --no-sync python ci/check_changelog_entries.py
+        run: just check-changelogs
 
       - name: Check zarr-metadata changelog entries
-        run: uv run --no-sync python ci/check_changelog_entries.py packages/zarr-metadata/changes
+        run: just check-changelogs packages/zarr-metadata/changes
 
       - name: Check zarr-indexing changelog entries
-        run: uv run --no-sync python ci/check_changelog_entries.py packages/zarr-indexing/changes
+        run: just check-changelogs packages/zarr-indexing/changes
 
       - name: Check zarr-http-server changelog entries
-        run: uv run --no-sync python ci/check_changelog_entries.py packages/zarr-http-server/changes
+        run: just check-changelogs packages/zarr-http-server/changes

.github/workflows/codspeed.yml

@@ -31,10 +31,19 @@ jobs:
       uses: pypa/hatch@f647ed70d49adb885f53a27d1c7f5bdaeacf2c60
       with:
         version: '1.16.5'
+    # No interpreter is set up in this job on purpose. Benchmarks are only comparable
+    # across runs if the interpreter underneath them does not move: adding a pinned
+    # Python here measured a uniform ~13% slowdown on every benchmark, because hatch
+    # then built the environment on that interpreter instead of the runner's own.
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Run the benchmarks
       uses: CodSpeedHQ/action@373d6868929f444bc08d901fd0eb0ad52a8875ea # v5.2.1
       env:
         ZARR_BENCHMARK_CLEAR_CACHE: '1'
       with:
           mode: walltime
-          run: hatch run test.py3.12-minimal:pytest tests/benchmarks --codspeed
+          run: HATCH_ENV=test.py3.12-minimal just benchmark-codspeed

.github/workflows/docs.yml

@@ -23,18 +23,22 @@ jobs:
         with:
           persist-credentials: false
       - uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
-      - run: uv sync --group docs
+      - name: Install just
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+        with:
+          repo: casey/just
+          version: 1.58.0
       # Fast source-level guards that need no built site, so they run before the (slower)
       # build for a quick failure: every public export is in the API reference, and no
       # docstring/Markdown carries reStructuredText markup that MkDocs won't render.
-      - run: uv run python ci/check_documented_exports.py docs/api
-      - run: uv run python ci/lint_docs.py
+      - run: just check-doc-exports
+      - run: just lint-docs
       # --strict turns warnings into errors, so a docs code block that fails to execute
       # at build time (e.g. a non-exec python fence disrupting a later exec="true" block)
       # fails CI instead of merging as a silent warning.
-      - run: uv run mkdocs build --strict
+      - run: just docs-build
         env:
           DISABLE_MKDOCS_2_WARNING: "true"
           NO_MKDOCS_2_WARNING: "true"
-      - run: uv run python ci/check_unlinked_types.py
+      - run: just check-doc-links
         continue-on-error: true

.github/workflows/gpu_test.yml

@@ -67,17 +67,24 @@ jobs:
       uses: pypa/hatch@f647ed70d49adb885f53a27d1c7f5bdaeacf2c60
       with:
         version: '1.16.5'
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
+    # Two names for the same environment on purpose: `just setup` builds whatever
+    # HATCH_ENV points at, while `just gpu` reads GPU_HATCH_ENV so that an
+    # ambient HATCH_ENV can never redirect `pytest -m gpu` into a CPU environment.
     - name: Set Up Hatch Env
       env:
         HATCH_ENV: gputest.py${{ matrix.python-version }}
       run: |
-        hatch env create "$HATCH_ENV"
-        hatch env run -e "$HATCH_ENV" list-env
+        just setup
     - name: Run Tests
       env:
-        HATCH_ENV: gputest.py${{ matrix.python-version }}
+        GPU_HATCH_ENV: gputest.py${{ matrix.python-version }}
       run: |
-        hatch env run --env "$HATCH_ENV" run-coverage
+        just gpu
 
     - name: Upload coverage
       uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f  # v7.0.0

.github/workflows/hypothesis.yaml

@@ -65,12 +65,16 @@ jobs:
       uses: pypa/hatch@f647ed70d49adb885f53a27d1c7f5bdaeacf2c60
       with:
         version: '1.16.5'
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Set Up Hatch Env
       env:
         HATCH_ENV: test.py${{ matrix.python-version }}-${{ matrix.dependency-set }}
       run: |
-        hatch env create "$HATCH_ENV"
-        hatch env run -e "$HATCH_ENV" list-env
+        just setup
     # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache
     - name: Restore cached hypothesis directory
       id: restore-hypothesis-cache
@@ -89,7 +93,7 @@ jobs:
         PYTEST_ADDOPTS: "--report-log=output-${{ matrix.python-version }}-log.jsonl"
       run: |
         echo "Using Hypothesis profile: $HYPOTHESIS_PROFILE"
-        hatch env run --env "$HATCH_ENV" run-hypothesis
+        just hypothesis
 
     # explicitly save the cache so it gets updated, also do this even if it fails.
     - name: Save cached hypothesis directory

.github/workflows/lint.yml

@@ -30,4 +30,26 @@ jobs:
         uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
         with:
           enable-cache: true
-      - uses: j178/prek-action@4e14d07f9231acabce116ccfca13b13dd9755ece # v3.0.0
+      - name: Install just
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+        with:
+          repo: casey/just
+          version: 1.58.0
+      # `uvx prek` builds each hook's environment from scratch, so cache them the
+      # way the prek action used to. Keyed on the hook config: a new pinned rev or
+      # a new hook is exactly when the cached environments stop being valid.
+      - name: Cache prek hook environments
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
+        with:
+          path: ~/.cache/prek
+          # Justfile is hashed too: prek_version lives there, and a bumped prek
+          # must not restore a store built by the previous one. No restore-keys
+          # fallback for the same reason.
+          key: prek-${{ runner.os }}-${{ hashFiles('.pre-commit-config.yaml', 'Justfile') }}
+      - name: Lint
+        run: just lint
+      - name: Check justfile formatting
+        # After the linters, and never masking them: this is cosmetic, and a
+        # mis-formatted recipe should not cost someone their ruff/mypy results.
+        if: always()
+        run: just just-check

.github/workflows/test.yml

@@ -69,18 +69,22 @@ jobs:
       uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
     - name: Install Hatch
       run: python -m pip install hatch==1.16.5
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Set Up Hatch Env
       env:
         HATCH_ENV: test.py${{ matrix.python-version }}-${{ matrix.dependency-set }}
       run: |
-        hatch env create "$HATCH_ENV"
-        hatch env run -e "$HATCH_ENV" list-env
+        just setup
     - name: Run Tests
       env:
         HYPOTHESIS_PROFILE: ci
         HATCH_ENV: test.py${{ matrix.python-version }}-${{ matrix.dependency-set }}
       run: |
-        hatch env run --env "$HATCH_ENV" run-coverage
+        just coverage
     - name: Upload coverage
       if: ${{ matrix.dependency-set == 'optional' && matrix.os == 'ubuntu-latest' }}
       uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v7.0.0
@@ -118,17 +122,21 @@ jobs:
       uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
     - name: Install Hatch
       run: python -m pip install hatch==1.16.5
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Set Up Hatch Env
       env:
         HATCH_ENV: ${{ matrix.dependency-set }}
       run: |
-        hatch env create "$HATCH_ENV"
-        hatch env run -e "$HATCH_ENV" list-env
+        just setup
     - name: Run Tests
       env:
         HATCH_ENV: ${{ matrix.dependency-set }}
       run: |
-        hatch env run --env "$HATCH_ENV" run-coverage
+        just coverage
     - name: Upload coverage
       uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v7.0.0
       with:
@@ -153,12 +161,17 @@ jobs:
       uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
     - name: Install Hatch
       run: python -m pip install hatch==1.16.5
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Set Up Hatch Env
       run: |
-        hatch run doctest:pip list
+        HATCH_ENV=doctest just setup
     - name: Run Tests
       run: |
-        hatch run doctest:test
+        just doctest
 
   benchmarks:
     name: Benchmark smoke test
@@ -177,11 +190,16 @@ jobs:
       uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
     - name: Install Hatch
       run: python -m pip install hatch==1.16.5
+    - name: Install just
+      uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
+      with:
+        repo: casey/just
+        version: 1.58.0
     - name: Run Benchmarks
       env:
         ZARR_BENCHMARK_CLEAR_CACHE: '1'
       run: |
-        hatch env run --env "test.py3.13-minimal" run-benchmark
+        HATCH_ENV=test.py3.13-minimal just benchmark
 
   test-complete:
     name: Test complete

.github/workflows/zarr-http-server.yml

@@ -53,11 +53,10 @@ jobs:
       - name: Set up Python ${{ matrix.python-version }}
         run: uv python install ${{ matrix.python-version }}
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Sync test dependency groups
         # The examples group carries the deps the README examples need, so the
         # test that reads a served array back with a zarr client runs here
@@ -80,11 +79,10 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Run ruff
         run: just lint
 
@@ -106,11 +104,10 @@ jobs:
       - name: Set up Python
         run: uv python install 3.12
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Sync test dependency group
         run: uv sync --group test --python 3.12
       - name: Run mypy
@@ -132,11 +129,10 @@ jobs:
         with:
           enable-cache: true
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Build docs
         run: just docs-check
 

.github/workflows/zarr-indexing.yml

@@ -40,11 +40,10 @@ jobs:
         with:
           enable-cache: true
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Set up Python ${{ matrix.python-version }}
         run: uv python install ${{ matrix.python-version }}
       # The suite imports nothing from `zarr`; it runs against the repo-root
@@ -73,11 +72,10 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@bec219d24cd3e171d82865faccec33120bb574f4 # v10.1.0
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Run ruff
         # The ruff version pin lives in packages/zarr-indexing/justfile.
         run: just lint
@@ -102,11 +100,10 @@ jobs:
       - name: Sync test dependency group
         run: uv sync --group test --python 3.12
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Run pyright
         # The pyright invocation lives in packages/zarr-indexing/justfile.
         run: just typecheck
@@ -127,11 +124,10 @@ jobs:
         with:
           enable-cache: true
       - name: Install just
-        uses: extractions/setup-just@53165ef7e734c5c07cb06b3c8e7b647c5aa16db3 # v4
+        uses: extractions/setup-crate@7577c1bdf2d95e6d65d532788f35ed79d4b1dda2 # v2.0.1
         with:
-          # Pin the tool, not just the action: without this the action
-          # installs whatever just is newest at run time.
-          just-version: 1.58.0
+          repo: casey/just
+          version: 1.58.0
       - name: Build docs
         # The strict mkdocs build lives in packages/zarr-indexing/justfile.
         run: just docs-check