From 271095360bf262a56ff155f24a521ff8cd146c9e Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:02:07 -0700
Subject: [PATCH 01/13] Automatically run setup steps based on environment
 kinds

---
 README.md   |   8 +--
 action.yml  | 195 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 example.yml |   5 +-
 3 files changed, 197 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index cbe901f..6255e63 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,9 @@ A GitHub Action to run a Calkit project's pipeline and optionally save results
 
 The example workflow below shows how to run a Calkit project, saving results.
 Note the permissions, concurrency, and checkout options.
+The action detects required environment kinds from `calkit.yaml` and sets up
+needed tooling (for example Calkit via `uv`, Julia, Pixi, Conda, R, MATLAB,
+and Docker Buildx) before running.
 
 <!-- Do not edit the snippet below since it is automatically populated -->
 <!-- snippet:example.yml:start -->
@@ -44,10 +47,7 @@ jobs:
         run: |
           git config user.name github-actions[bot]
           git config user.email 41898282+github-actions[bot]@users.noreply.github.com
-      - name: Setup uv
-        uses: astral-sh/setup-uv@v5
-      - name: Install Calkit
-        run: uv tool install calkit-python
+      # Calkit automatically runs necessary setup actions based on environments
       - name: Run Calkit
         uses: calkit/run-action@v2
 ```
diff --git a/action.yml b/action.yml
index c4617c3..3375fd3 100644
--- a/action.yml
+++ b/action.yml
@@ -10,7 +10,8 @@ inputs:
     description: Whether or not to save (commit and push) results to Git and DVC remotes.
     default: "true"
   dvc_token:
-    description: DVC token for pushing results. If not provided, will be obtained
+    description:
+      DVC token for pushing results. If not provided, will be obtained
       via GitHub OIDC.
     required: false
   pull_dvc:
@@ -29,17 +30,201 @@ outputs: {}
 runs:
   using: composite
   steps:
+    - name: Detect setup requirements
+      id: detect
+      shell: bash
+      run: |
+        set -euo pipefail
+
+        has_kind() {
+          local kind="$1"
+          grep -Eiq "^[[:space:]]*kind:[[:space:]]*[\"']?${kind}([\"']?[[:space:]#]|$)" calkit.yaml
+        }
+
+        if command -v calkit >/dev/null 2>&1; then
+          calkit_missing=false
+        else
+          calkit_missing=true
+        fi
+        echo "calkit_missing=${calkit_missing}" >> "$GITHUB_OUTPUT"
+
+        if command -v uv >/dev/null 2>&1; then
+          uv_missing=false
+        else
+          uv_missing=true
+        fi
+        echo "uv_missing=${uv_missing}" >> "$GITHUB_OUTPUT"
+
+        if command -v python >/dev/null 2>&1 || command -v python3 >/dev/null 2>&1; then
+          python_missing=false
+        else
+          python_missing=true
+        fi
+
+        if command -v conda >/dev/null 2>&1; then
+          conda_missing=false
+        else
+          conda_missing=true
+        fi
+
+        if command -v pixi >/dev/null 2>&1; then
+          pixi_missing=false
+        else
+          pixi_missing=true
+        fi
+
+        if command -v julia >/dev/null 2>&1; then
+          julia_missing=false
+        else
+          julia_missing=true
+        fi
+
+        if command -v Rscript >/dev/null 2>&1 || command -v R >/dev/null 2>&1; then
+          r_missing=false
+        else
+          r_missing=true
+        fi
+
+        if command -v matlab >/dev/null 2>&1; then
+          matlab_missing=false
+        else
+          matlab_missing=true
+        fi
+
+        if command -v docker >/dev/null 2>&1 && docker buildx version >/dev/null 2>&1; then
+          docker_buildx_missing=false
+        else
+          docker_buildx_missing=true
+        fi
+
+        needs_python=false
+        needs_conda=false
+        needs_pixi=false
+        needs_julia=false
+        needs_r=false
+        needs_matlab=false
+        needs_docker=false
+        unsupported_kinds=""
+
+        if [ -f calkit.yaml ]; then
+          if has_kind "uv-venv" || has_kind "venv"; then
+            if [ "$python_missing" = true ]; then
+              needs_python=true
+            fi
+          fi
+          if has_kind "conda"; then
+            if [ "$conda_missing" = true ]; then
+              needs_conda=true
+            fi
+            if [ "$python_missing" = true ]; then
+              needs_python=true
+            fi
+          fi
+          if has_kind "pixi"; then
+            if [ "$pixi_missing" = true ]; then
+              needs_pixi=true
+            fi
+          fi
+          if has_kind "julia"; then
+            if [ "$julia_missing" = true ]; then
+              needs_julia=true
+            fi
+          fi
+          if has_kind "renv"; then
+            if [ "$r_missing" = true ]; then
+              needs_r=true
+            fi
+          fi
+          if has_kind "matlab"; then
+            if [ "$matlab_missing" = true ]; then
+              needs_matlab=true
+            fi
+          fi
+          if has_kind "docker"; then
+            if [ "$docker_buildx_missing" = true ]; then
+              needs_docker=true
+            fi
+          fi
+
+          # These kinds do not have a direct setup action in this composite action.
+          if has_kind "ssh"; then unsupported_kinds="${unsupported_kinds}ssh,"; fi
+          if has_kind "slurm"; then unsupported_kinds="${unsupported_kinds}slurm,"; fi
+          unsupported_kinds="${unsupported_kinds%,}"
+        fi
+
+        echo "needs_python=${needs_python}" >> "$GITHUB_OUTPUT"
+        echo "needs_conda=${needs_conda}" >> "$GITHUB_OUTPUT"
+        echo "needs_pixi=${needs_pixi}" >> "$GITHUB_OUTPUT"
+        echo "needs_julia=${needs_julia}" >> "$GITHUB_OUTPUT"
+        echo "needs_r=${needs_r}" >> "$GITHUB_OUTPUT"
+        echo "needs_matlab=${needs_matlab}" >> "$GITHUB_OUTPUT"
+        echo "needs_docker=${needs_docker}" >> "$GITHUB_OUTPUT"
+        echo "unsupported_kinds=${unsupported_kinds}" >> "$GITHUB_OUTPUT"
+
+    - name: Setup uv
+      if: ${{ steps.detect.outputs.calkit_missing == 'true' && steps.detect.outputs.uv_missing == 'true' }}
+      uses: astral-sh/setup-uv@v5
+
+    - name: Install Calkit
+      if: ${{ steps.detect.outputs.calkit_missing == 'true' }}
+      shell: bash
+      run: |
+        uv tool install calkit-python
+        echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
+    - name: Setup Python
+      if: ${{ steps.detect.outputs.needs_python == 'true' }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.x"
+
+    - name: Setup Miniconda
+      if: ${{ steps.detect.outputs.needs_conda == 'true' }}
+      uses: conda-incubator/setup-miniconda@v3
+      with:
+        auto-activate-base: true
+
+    - name: Setup Pixi
+      if: ${{ steps.detect.outputs.needs_pixi == 'true' }}
+      uses: prefix-dev/setup-pixi@v0
+
+    - name: Setup Julia
+      if: ${{ steps.detect.outputs.needs_julia == 'true' }}
+      uses: julia-actions/setup-julia@v2
+      with:
+        version: "1"
+
+    - name: Setup R
+      if: ${{ steps.detect.outputs.needs_r == 'true' }}
+      uses: r-lib/actions/setup-r@v2
+
+    - name: Setup MATLAB
+      if: ${{ steps.detect.outputs.needs_matlab == 'true' }}
+      uses: matlab-actions/setup-matlab@v2
+
+    - name: Setup Docker Buildx
+      if: ${{ steps.detect.outputs.needs_docker == 'true' }}
+      uses: docker/setup-buildx-action@v3
+
+    - name: Report unsupported environment kinds
+      if: ${{ steps.detect.outputs.unsupported_kinds != '' }}
+      shell: bash
+      run: |
+        echo "::notice::Detected environment kinds without explicit setup action: ${{ steps.detect.outputs.unsupported_kinds }}"
+
     - name: Restore DVC cache for current branch
       if: ${{ inputs.cache_dvc == 'true' }}
       id: cache-dvc-restore
       uses: actions/cache/restore@v5
       with:
         path: .dvc/cache
-        key: ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
+        key:
+          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
           github.sha }}
         restore-keys: |
           ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-
           ${{ runner.os }}-dvc-cache-${{ github.event.repository.default_branch }}-
+
     - name: Get GitHub OIDC token
       if: ${{ !inputs.dvc_token && (inputs.save == 'true' || inputs.pull_dvc ==
         'true') }}
@@ -53,6 +238,7 @@ runs:
         fi
         echo "::add-mask::$OIDC_TOKEN"
         echo "oidc-token=$OIDC_TOKEN" >> $GITHUB_OUTPUT
+
     - name: Exchange OIDC token for Calkit token
       if: ${{ !inputs.dvc_token && (inputs.save == 'true' || inputs.pull_dvc ==
         'true') }}
@@ -68,6 +254,7 @@ runs:
         fi
         echo "::add-mask::$CALKIT_TOKEN"
         echo "calkit-token=$CALKIT_TOKEN" >> $GITHUB_OUTPUT
+
     - run: calkit config remote-auth
       if: ${{ inputs.save == 'true' || inputs.pull_dvc == 'true' }}
       shell: bash
@@ -86,11 +273,13 @@ runs:
       env:
         CALKIT_TOKEN: ${{ inputs.dvc_token || steps.get-calkit-token.outputs.calkit-token }}
         CALKIT_DVC_TOKEN: ${{ inputs.dvc_token || steps.get-calkit-token.outputs.calkit-token }}
+
     - name: Save DVC cache
       if: ${{ inputs.cache_dvc == 'true' }}
       id: cache-dvc-save
       uses: actions/cache/save@v5
       with:
         path: .dvc/cache
-        key: ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
+        key:
+          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
           github.sha }}
diff --git a/example.yml b/example.yml
index 8e789de..9a55f0e 100644
--- a/example.yml
+++ b/example.yml
@@ -31,9 +31,6 @@ jobs:
         run: |
           git config user.name github-actions[bot]
           git config user.email 41898282+github-actions[bot]@users.noreply.github.com
-      - name: Setup uv
-        uses: astral-sh/setup-uv@v5
-      - name: Install Calkit
-        run: uv tool install calkit-python
+      # Calkit automatically runs necessary setup actions based on environments
       - name: Run Calkit
         uses: calkit/run-action@v2

From 4e3a073f9b7ca7ac398085a41c11fe5de95457a2 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:09:24 -0700
Subject: [PATCH 02/13] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 action.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/action.yml b/action.yml
index 3375fd3..e6b3e83 100644
--- a/action.yml
+++ b/action.yml
@@ -162,7 +162,7 @@ runs:
         echo "unsupported_kinds=${unsupported_kinds}" >> "$GITHUB_OUTPUT"
 
     - name: Setup uv
-      if: ${{ steps.detect.outputs.calkit_missing == 'true' && steps.detect.outputs.uv_missing == 'true' }}
+      if: ${{ steps.detect.outputs.uv_missing == 'true' }}
       uses: astral-sh/setup-uv@v5
 
     - name: Install Calkit

From 42b0b3abf0b1b2cb6e021818fc670b4b6ce2b464 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:10:50 -0700
Subject: [PATCH 03/13] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 action.yml | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/action.yml b/action.yml
index e6b3e83..667113a 100644
--- a/action.yml
+++ b/action.yml
@@ -218,9 +218,8 @@ runs:
       uses: actions/cache/restore@v5
       with:
         path: .dvc/cache
-        key:
-          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
-          github.sha }}
+        key: >-
+          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{ github.sha }}
         restore-keys: |
           ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-
           ${{ runner.os }}-dvc-cache-${{ github.event.repository.default_branch }}-

From e539d822c427b3e14c357fa7271a99f95f3367a8 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:11:39 -0700
Subject: [PATCH 04/13] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 action.yml | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/action.yml b/action.yml
index 667113a..ac51519 100644
--- a/action.yml
+++ b/action.yml
@@ -279,6 +279,5 @@ runs:
       uses: actions/cache/save@v5
       with:
         path: .dvc/cache
-        key:
-          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{
-          github.sha }}
+        key: >-
+          ${{ runner.os }}-dvc-cache-${{ github.head_ref || github.ref_name }}-${{ github.sha }}

From f858ab8e3de7bcf37e384bcf9a2dc283e5601f26 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:12:10 -0700
Subject: [PATCH 05/13] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 example.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/example.yml b/example.yml
index 9a55f0e..6e26cdc 100644
--- a/example.yml
+++ b/example.yml
@@ -31,6 +31,6 @@ jobs:
         run: |
           git config user.name github-actions[bot]
           git config user.email 41898282+github-actions[bot]@users.noreply.github.com
-      # Calkit automatically runs necessary setup actions based on environments
+      # This action automatically runs necessary setup steps based on environments
       - name: Run Calkit
         uses: calkit/run-action@v2

From c5f3652a334371a3c116eba633ef379cc9e9864f Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Wed, 3 Jun 2026 00:12:19 +0000
Subject: [PATCH 06/13] Sync README snippet from example.yml

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 6255e63..6a78158 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ jobs:
         run: |
           git config user.name github-actions[bot]
           git config user.email 41898282+github-actions[bot]@users.noreply.github.com
-      # Calkit automatically runs necessary setup actions based on environments
+      # This action automatically runs necessary setup steps based on environments
       - name: Run Calkit
         uses: calkit/run-action@v2
 ```

From a9f57667c61d4aa0075f64a8da7b12825a254295 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 17:13:02 -0700
Subject: [PATCH 07/13] Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 action.yml | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/action.yml b/action.yml
index ac51519..4de2ac8 100644
--- a/action.yml
+++ b/action.yml
@@ -141,8 +141,12 @@ runs:
             fi
           fi
           if has_kind "docker"; then
-            if [ "$docker_buildx_missing" = true ]; then
-              needs_docker=true
+            if command -v docker >/dev/null 2>&1; then
+              if [ "$docker_buildx_missing" = true ]; then
+                needs_docker=true
+              fi
+            else
+              unsupported_kinds="${unsupported_kinds}docker,"
             fi
           fi
 

From 6da1b4169a7fc6f6170a6ba458bb4fdadb15981e Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 18:16:55 -0700
Subject: [PATCH 08/13] Address PR comments

---
 action.yml | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/action.yml b/action.yml
index 4de2ac8..5dedb15 100644
--- a/action.yml
+++ b/action.yml
@@ -98,20 +98,29 @@ runs:
         fi
 
         needs_python=false
+        needs_uv=false
         needs_conda=false
         needs_pixi=false
         needs_julia=false
         needs_r=false
         needs_matlab=false
         needs_docker=false
+        docker_cli_missing=false
         unsupported_kinds=""
 
+        if [ "$calkit_missing" = true ]; then
+          needs_uv=true
+        fi
+
         if [ -f calkit.yaml ]; then
           if has_kind "uv-venv" || has_kind "venv"; then
             if [ "$python_missing" = true ]; then
               needs_python=true
             fi
           fi
+          if has_kind "uv-venv"; then
+            needs_uv=true
+          fi
           if has_kind "conda"; then
             if [ "$conda_missing" = true ]; then
               needs_conda=true
@@ -146,7 +155,7 @@ runs:
                 needs_docker=true
               fi
             else
-              unsupported_kinds="${unsupported_kinds}docker,"
+              docker_cli_missing=true
             fi
           fi
 
@@ -157,16 +166,18 @@ runs:
         fi
 
         echo "needs_python=${needs_python}" >> "$GITHUB_OUTPUT"
+        echo "needs_uv=${needs_uv}" >> "$GITHUB_OUTPUT"
         echo "needs_conda=${needs_conda}" >> "$GITHUB_OUTPUT"
         echo "needs_pixi=${needs_pixi}" >> "$GITHUB_OUTPUT"
         echo "needs_julia=${needs_julia}" >> "$GITHUB_OUTPUT"
         echo "needs_r=${needs_r}" >> "$GITHUB_OUTPUT"
         echo "needs_matlab=${needs_matlab}" >> "$GITHUB_OUTPUT"
         echo "needs_docker=${needs_docker}" >> "$GITHUB_OUTPUT"
+        echo "docker_cli_missing=${docker_cli_missing}" >> "$GITHUB_OUTPUT"
         echo "unsupported_kinds=${unsupported_kinds}" >> "$GITHUB_OUTPUT"
 
     - name: Setup uv
-      if: ${{ steps.detect.outputs.uv_missing == 'true' }}
+      if: ${{ steps.detect.outputs.needs_uv == 'true' && steps.detect.outputs.uv_missing == 'true' }}
       uses: astral-sh/setup-uv@v5
 
     - name: Install Calkit
@@ -216,6 +227,12 @@ runs:
       run: |
         echo "::notice::Detected environment kinds without explicit setup action: ${{ steps.detect.outputs.unsupported_kinds }}"
 
+    - name: Report missing Docker CLI for docker environments
+      if: ${{ steps.detect.outputs.docker_cli_missing == 'true' }}
+      shell: bash
+      run: |
+        echo "::notice::Detected kind 'docker' in calkit.yaml, but Docker CLI is not available on this runner. Install Docker on the runner to use docker environments."
+
     - name: Restore DVC cache for current branch
       if: ${{ inputs.cache_dvc == 'true' }}
       id: cache-dvc-restore

From c98e3fd0b1f60d8ee3f12dccc399adfdc1356028 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 19:18:14 -0700
Subject: [PATCH 09/13] Refine

---
 action.yml | 162 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 95 insertions(+), 67 deletions(-)

diff --git a/action.yml b/action.yml
index 5dedb15..9be7282 100644
--- a/action.yml
+++ b/action.yml
@@ -30,36 +30,67 @@ outputs: {}
 runs:
   using: composite
   steps:
+    - name: Check for uv and Calkit
+      id: tools
+      shell: bash
+      run: |
+        set -euo pipefail
+        if command -v uv >/dev/null 2>&1; then
+          echo "uv_missing=false" >> "$GITHUB_OUTPUT"
+        else
+          echo "uv_missing=true" >> "$GITHUB_OUTPUT"
+        fi
+        if command -v calkit >/dev/null 2>&1; then
+          echo "calkit_missing=false" >> "$GITHUB_OUTPUT"
+        else
+          echo "calkit_missing=true" >> "$GITHUB_OUTPUT"
+        fi
+
+    # uv is only needed up front to install Calkit; uv-venv projects that
+    # need uv but already have Calkit are handled by the uv step after
+    # detection.
+    - name: Setup uv
+      if: ${{ steps.tools.outputs.uv_missing == 'true' && steps.tools.outputs.calkit_missing == 'true' }}
+      uses: astral-sh/setup-uv@v5
+
+    - name: Install Calkit
+      if: ${{ steps.tools.outputs.calkit_missing == 'true' }}
+      shell: bash
+      run: |
+        uv tool install calkit-python
+        echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
     - name: Detect setup requirements
       id: detect
       shell: bash
       run: |
         set -euo pipefail
 
+        # Let Calkit parse its own config so we only look at the
+        # `environments` section (a real YAML parse that also resolves
+        # includes), rather than grepping every `kind:` in the file --
+        # pipeline stages, dependencies, datasets, etc. all use `kind:` too.
+        kinds=$(calkit list environments 2>/dev/null \
+          | grep -E '^[[:space:]]+kind:' \
+          | sed -E 's/^[[:space:]]+kind:[[:space:]]*//; s/[[:space:]]+#.*$//' \
+          | tr -d "\"'" | sort -u || true)
+        echo "Detected environment kinds: $(echo "$kinds" | paste -sd, -)"
+
         has_kind() {
-          local kind="$1"
-          grep -Eiq "^[[:space:]]*kind:[[:space:]]*[\"']?${kind}([\"']?[[:space:]#]|$)" calkit.yaml
+          printf '%s\n' "$kinds" | grep -qx "$1"
         }
 
-        if command -v calkit >/dev/null 2>&1; then
-          calkit_missing=false
+        if command -v python >/dev/null 2>&1 || command -v python3 >/dev/null 2>&1; then
+          python_missing=false
         else
-          calkit_missing=true
+          python_missing=true
         fi
-        echo "calkit_missing=${calkit_missing}" >> "$GITHUB_OUTPUT"
 
         if command -v uv >/dev/null 2>&1; then
           uv_missing=false
         else
           uv_missing=true
         fi
-        echo "uv_missing=${uv_missing}" >> "$GITHUB_OUTPUT"
-
-        if command -v python >/dev/null 2>&1 || command -v python3 >/dev/null 2>&1; then
-          python_missing=false
-        else
-          python_missing=true
-        fi
 
         if command -v conda >/dev/null 2>&1; then
           conda_missing=false
@@ -108,63 +139,64 @@ runs:
         docker_cli_missing=false
         unsupported_kinds=""
 
-        if [ "$calkit_missing" = true ]; then
-          needs_uv=true
-        fi
-
-        if [ -f calkit.yaml ]; then
-          if has_kind "uv-venv" || has_kind "venv"; then
-            if [ "$python_missing" = true ]; then
-              needs_python=true
-            fi
+        if has_kind "uv-venv" || has_kind "venv" || has_kind "uv"; then
+          if [ "$python_missing" = true ]; then
+            needs_python=true
           fi
-          if has_kind "uv-venv"; then
+        fi
+        # uv is installed up front to install Calkit, so it is normally
+        # already present here; this covers the case where Calkit was
+        # pre-installed (so we skipped the initial uv setup) but uv is not.
+        if has_kind "uv-venv" || has_kind "uv"; then
+          if [ "$uv_missing" = true ]; then
             needs_uv=true
           fi
-          if has_kind "conda"; then
-            if [ "$conda_missing" = true ]; then
-              needs_conda=true
-            fi
-            if [ "$python_missing" = true ]; then
-              needs_python=true
-            fi
+        fi
+        if has_kind "conda"; then
+          if [ "$conda_missing" = true ]; then
+            needs_conda=true
           fi
-          if has_kind "pixi"; then
-            if [ "$pixi_missing" = true ]; then
-              needs_pixi=true
-            fi
+          if [ "$python_missing" = true ]; then
+            needs_python=true
           fi
-          if has_kind "julia"; then
-            if [ "$julia_missing" = true ]; then
-              needs_julia=true
-            fi
+        fi
+        if has_kind "pixi"; then
+          if [ "$pixi_missing" = true ]; then
+            needs_pixi=true
           fi
-          if has_kind "renv"; then
-            if [ "$r_missing" = true ]; then
-              needs_r=true
-            fi
+        fi
+        if has_kind "julia"; then
+          if [ "$julia_missing" = true ]; then
+            needs_julia=true
           fi
-          if has_kind "matlab"; then
-            if [ "$matlab_missing" = true ]; then
-              needs_matlab=true
-            fi
+        fi
+        if has_kind "renv"; then
+          if [ "$r_missing" = true ]; then
+            needs_r=true
           fi
-          if has_kind "docker"; then
-            if command -v docker >/dev/null 2>&1; then
-              if [ "$docker_buildx_missing" = true ]; then
-                needs_docker=true
-              fi
-            else
-              docker_cli_missing=true
+        fi
+        if has_kind "matlab"; then
+          if [ "$matlab_missing" = true ]; then
+            needs_matlab=true
+          fi
+        fi
+        if has_kind "docker"; then
+          if command -v docker >/dev/null 2>&1; then
+            if [ "$docker_buildx_missing" = true ]; then
+              needs_docker=true
             fi
+          else
+            docker_cli_missing=true
           fi
-
-          # These kinds do not have a direct setup action in this composite action.
-          if has_kind "ssh"; then unsupported_kinds="${unsupported_kinds}ssh,"; fi
-          if has_kind "slurm"; then unsupported_kinds="${unsupported_kinds}slurm,"; fi
-          unsupported_kinds="${unsupported_kinds%,}"
         fi
 
+        # These kinds do not have a direct setup action in this composite action.
+        if has_kind "ssh"; then unsupported_kinds="${unsupported_kinds}ssh,"; fi
+        if has_kind "slurm"; then unsupported_kinds="${unsupported_kinds}slurm,"; fi
+        if has_kind "pbs"; then unsupported_kinds="${unsupported_kinds}pbs,"; fi
+        if has_kind "nix"; then unsupported_kinds="${unsupported_kinds}nix,"; fi
+        unsupported_kinds="${unsupported_kinds%,}"
+
         echo "needs_python=${needs_python}" >> "$GITHUB_OUTPUT"
         echo "needs_uv=${needs_uv}" >> "$GITHUB_OUTPUT"
         echo "needs_conda=${needs_conda}" >> "$GITHUB_OUTPUT"
@@ -176,17 +208,10 @@ runs:
         echo "docker_cli_missing=${docker_cli_missing}" >> "$GITHUB_OUTPUT"
         echo "unsupported_kinds=${unsupported_kinds}" >> "$GITHUB_OUTPUT"
 
-    - name: Setup uv
-      if: ${{ steps.detect.outputs.needs_uv == 'true' && steps.detect.outputs.uv_missing == 'true' }}
+    - name: Setup uv for uv and uv-venv environments
+      if: ${{ steps.detect.outputs.needs_uv == 'true' }}
       uses: astral-sh/setup-uv@v5
 
-    - name: Install Calkit
-      if: ${{ steps.detect.outputs.calkit_missing == 'true' }}
-      shell: bash
-      run: |
-        uv tool install calkit-python
-        echo "$HOME/.local/bin" >> "$GITHUB_PATH"
-
     - name: Setup Python
       if: ${{ steps.detect.outputs.needs_python == 'true' }}
       uses: actions/setup-python@v5
@@ -281,12 +306,15 @@ runs:
       env:
         CALKIT_TOKEN: ${{ inputs.dvc_token || steps.get-calkit-token.outputs.calkit-token }}
         CALKIT_DVC_TOKEN: ${{ inputs.dvc_token || steps.get-calkit-token.outputs.calkit-token }}
+
     - run: calkit dvc pull
       if: ${{ inputs.pull_dvc == 'true' }}
       shell: bash
       continue-on-error: true
+
     - run: calkit run ${{ inputs.run_args }}
       shell: bash
+
     - run: calkit save -am "Run pipeline"
       if: ${{ inputs.save == 'true' }}
       shell: bash

From 5b1be6c37da7758770def9dd31ffa1a461b8c70f Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 19:41:06 -0700
Subject: [PATCH 10/13] Add test

---
 .github/workflows/test.yml | 56 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 .github/workflows/test.yml

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..81b5795
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,56 @@
+name: Test action
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+# Saving/pulling is disabled below, so no Calkit/DVC token (and no OIDC) is
+# needed and the default read-only token is sufficient.
+permissions:
+  contents: read
+
+jobs:
+  run-examples:
+    name: ${{ matrix.example.repo }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        # Each entry clones a real Calkit example project and runs a single
+        # lightweight stage so the action's environment setup is exercised
+        # without building the heavy `tex` (texlive/texlive Docker) env that
+        # these projects use for their paper-build stages. `target` must be a
+        # stage whose environment is the one we want to verify got installed.
+        # To cover another kind, add an example repo + a cheap target here.
+        example:
+          - repo: example-basic
+            target: collect-data # uses the `py` (uv-venv) environment
+            verify: uv --version
+          - repo: example-julia
+            target: run-script # uses the `main` (julia) environment
+            verify: julia --version
+    steps:
+      # The composite action's steps run in $GITHUB_WORKSPACE, and it reads
+      # ./calkit.yaml from there, so the example project must be the workspace
+      # root. The workspace is empty at job start, so cloning into "." works;
+      # we then check this action out into a subdirectory and reference it
+      # locally via `uses: ./_action`.
+      - name: Clone example project
+        run: git clone --depth 1 "https://github.com/calkit/${{ matrix.example.repo }}.git" .
+
+      - name: Check out this action
+        uses: actions/checkout@v4
+        with:
+          path: _action
+
+      - name: Run Calkit action
+        uses: ./_action
+        with:
+          save: "false"
+          pull_dvc: "false"
+          cache_dvc: "false"
+          run_args: ${{ matrix.example.target }}
+
+      - name: Verify expected tooling was installed
+        run: ${{ matrix.example.verify }}

From 7f55a85fd2abbfa2fbe2b9a40467f3e3e70dea82 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 19:57:40 -0700
Subject: [PATCH 11/13] Install juliaup

---
 action.yml | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/action.yml b/action.yml
index 9be7282..9dc5546 100644
--- a/action.yml
+++ b/action.yml
@@ -104,6 +104,15 @@ runs:
           pixi_missing=true
         fi
 
+        # Calkit manages Julia versions via juliaup (e.g. `juliaup add
+        # 1.11.7` for a `julia: "1.11.7"` environment). We install juliaup
+        # only when the runner has no Julia tooling at all; if the user
+        # already set up julia or juliaup themselves, we leave it alone.
+        if command -v juliaup >/dev/null 2>&1; then
+          juliaup_missing=false
+        else
+          juliaup_missing=true
+        fi
         if command -v julia >/dev/null 2>&1; then
           julia_missing=false
         else
@@ -166,7 +175,7 @@ runs:
           fi
         fi
         if has_kind "julia"; then
-          if [ "$julia_missing" = true ]; then
+          if [ "$juliaup_missing" = true ] && [ "$julia_missing" = true ]; then
             needs_julia=true
           fi
         fi
@@ -228,11 +237,14 @@ runs:
       if: ${{ steps.detect.outputs.needs_pixi == 'true' }}
       uses: prefix-dev/setup-pixi@v0
 
-    - name: Setup Julia
+    # Install juliaup (not a fixed Julia) so Calkit can install and select
+    # the exact Julia version(s) declared in each environment via
+    # `juliaup add`. The channel here is just a default bootstrap install.
+    - name: Setup juliaup
       if: ${{ steps.detect.outputs.needs_julia == 'true' }}
-      uses: julia-actions/setup-julia@v2
+      uses: julia-actions/install-juliaup@v2
       with:
-        version: "1"
+        channel: "1"
 
     - name: Setup R
       if: ${{ steps.detect.outputs.needs_r == 'true' }}

From 022f9359a0dab0c6a874837d4434aff14f2edcc0 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 20:05:13 -0700
Subject: [PATCH 12/13] Require juliaup

---
 .github/workflows/test.yml |  2 ++
 action.yml                 | 17 ++++++++---------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 81b5795..9bac880 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,6 +2,8 @@ name: Test action
 
 on:
   push:
+    branches:
+      - main
   pull_request:
   workflow_dispatch:
 
diff --git a/action.yml b/action.yml
index 9dc5546..53bcd0e 100644
--- a/action.yml
+++ b/action.yml
@@ -105,19 +105,18 @@ runs:
         fi
 
         # Calkit manages Julia versions via juliaup (e.g. `juliaup add
-        # 1.11.7` for a `julia: "1.11.7"` environment). We install juliaup
-        # only when the runner has no Julia tooling at all; if the user
-        # already set up julia or juliaup themselves, we leave it alone.
+        # 1.11.7` for a `julia: "1.11.7"` environment), so juliaup -- not a
+        # fixed Julia -- is what must be present. We deliberately gate only on
+        # juliaup and ignore any plain `julia` on the runner: hosted runner
+        # images ship a pinned Julia that usually won't match the project's
+        # required version, and without juliaup Calkit can't install the right
+        # one. Users who manage Julia themselves should install juliaup, which
+        # this then detects and leaves alone.
         if command -v juliaup >/dev/null 2>&1; then
           juliaup_missing=false
         else
           juliaup_missing=true
         fi
-        if command -v julia >/dev/null 2>&1; then
-          julia_missing=false
-        else
-          julia_missing=true
-        fi
 
         if command -v Rscript >/dev/null 2>&1 || command -v R >/dev/null 2>&1; then
           r_missing=false
@@ -175,7 +174,7 @@ runs:
           fi
         fi
         if has_kind "julia"; then
-          if [ "$juliaup_missing" = true ] && [ "$julia_missing" = true ]; then
+          if [ "$juliaup_missing" = true ]; then
             needs_julia=true
           fi
         fi

From ee89fc5f8e37dfe000c6719509ac6a5b4c658012 Mon Sep 17 00:00:00 2001
From: Pete Bachant <petebachant@gmail.com>
Date: Tue, 2 Jun 2026 20:13:41 -0700
Subject: [PATCH 13/13] Add workflow to rotate tags

---
 .github/workflows/release.yml | 41 +++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 .github/workflows/release.yml

diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..9c284dd
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,41 @@
+name: Move floating version tags
+
+# When a release is published with a full semver tag (e.g. v2.3.1), move the
+# floating major (v2) and minor (v2.3) tags to point at it, so consumers
+# pinned to `@v2` or `@v2.3` get the new release. Prereleases (e.g.
+# v2.4.0-rc.1) are skipped, so you can publish them without shipping to
+# everyone on `@v2`.
+
+on:
+  release:
+    types: [published]
+
+permissions:
+  contents: write
+
+jobs:
+  retag:
+    runs-on: ubuntu-latest
+    if: ${{ !github.event.release.prerelease }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Update major and minor tags
+        run: |
+          set -euo pipefail
+          TAG="${GITHUB_REF_NAME}" # e.g. v2.3.1
+          # Only move tags for plain vMAJOR.MINOR.PATCH releases.
+          if [[ ! "$TAG" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+            echo "::notice::Tag '$TAG' is not a vX.Y.Z release; not moving floating tags."
+            exit 0
+          fi
+          MAJOR="${TAG%%.*}" # v2
+          MINOR="${TAG%.*}"  # v2.3
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git tag -f "$MAJOR" "$TAG"
+          git tag -f "$MINOR" "$TAG"
+          git push -f origin "$MAJOR" "$MINOR"
+          echo "Moved $MAJOR and $MINOR -> $TAG"