Prune uv's CI cache (#135)

* Prune uv's CI cache

Just keep the downloaded packages to make cache operations faster.

* Be explicit about saving/restoring

* Please don't tell me cache won't allow to cache uv

* Try moving uv cache dir elsewhere

* jfc

* Remove debug

* Add changelog

CHANGELOG.md

@@ -6,6 +6,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased](https://github.com/hynek/build-and-inspect-python-package/compare/v2.7.0...main)
 
+### Changed
+
+- Use *uv*'s new `uv cache prune --ci` to only cache downloaded files.
+  This makes the cache smaller and faster to pack/unpack.
+  [#135](https://github.com/hynek/build-and-inspect-python-package/pull/135)
+
+
+### Fixed
+
+- Turns out, the default location of *uv*'s cache cannot be cached and [*actions/cache*](https://github.com/actions/cache) fails silently with an opaque "Path(s) specified in the action for caching do(es) not exist, hence no cache is being saved." log message.
+  We have moved the cache to `/tmp`.
+  [#135](https://github.com/hynek/build-and-inspect-python-package/pull/135)
+
 
 ## [2.7.0](https://github.com/hynek/build-and-inspect-python-package/compare/v2.6.0...v2.7.0) - 2024-07-17
 

action.yml

@@ -59,17 +59,17 @@ runs:
       run: curl -LsSf https://astral.sh/uv/install.sh | sh
       shell: bash
 
-    - name: Find uv cache and hash lock file
+    - name: Set uv cache and hash lock file
       run: |
-        echo "UV_CACHE=$(uv cache dir)" >>$GITHUB_ENV
+        echo "UV_CACHE_DIR=/tmp/baipp-uv_cache_dir" >>$GITHUB_ENV
 
         echo "REQS_HASH=$(sha256sum ${{ github.action_path }}/requirements/tools.txt | cut -d' ' -f1)" >>$GITHUB_ENV
       shell: bash
 
-    - name: Cache uv
+    - name: Setup uv cache
       uses: actions/cache@v4
       with:
-        path: ${{ env.UV_CACHE }}
+        path: ${{ env.UV_CACHE_DIR }}
         key: baipp-${{ env.REQS_HASH }}
 
     - name: Create venv for tools
@@ -107,13 +107,17 @@ runs:
         export SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct)
 
         if [[ "${{ inputs.skip-wheel }}" == "true" ]]; then
-          /tmp/baipp/bin/python -m build --installer=uv --sdist --outdir /tmp/baipp/dist
+          /tmp/baipp/bin/python -Im build --installer=uv --sdist --outdir /tmp/baipp/dist
         else
-          /tmp/baipp/bin/python -m build --installer=uv --outdir /tmp/baipp/dist
+          /tmp/baipp/bin/python -Im build --installer=uv --outdir /tmp/baipp/dist
         fi
       shell: bash
       working-directory: ${{ inputs.path }}
 
+    - name: Optimize uv cache for CI
+      run: uv cache prune --ci
+      shell: bash
+
     - name: Attest GitHub build provenance
       if: ${{ inputs.attest-build-provenance-github == 'true' }}
       uses: actions/attest-build-provenance@v1