Merge #6361: ci: better caching gh actions

a856b81f0e ci: drop unneeded comments (pasta)
189233b987 ci: handle ccache / depends based on build_target not host to avoid failing to cache all the linux 86_64 runs (pasta)
cbeeb9e00d ci: adjust caching strategy (pasta)
354d6a9aab ci: cache depends sources in a seperate step (pasta)

Pull request description:

  ## Issue being fixed or feature implemented
  Improve GitHub Actions caching to not have such large caches that get evicted frequently

  ## What was done?
  Use hash files on depends for depends related caching
  bring all depends sources under shared cache

  ## How Has This Been Tested?
  CI in my branches

  ## Breaking Changes
  None

  ## Checklist:
    _Go over all the following points, and put an `x` in all the boxes that apply._
  - [ ] I have performed a self-review of my own code
  - [ ] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have added or updated relevant unit/integration/functional/e2e tests
  - [ ] I have made corresponding changes to the documentation
  - [x] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  UdjinM6:
    utACK a856b81f0e

Tree-SHA512: f3d6cfeccfed0c811686a8becc548097b63c34a338cd5ff84445a8e9254c6aa03a394125c90aab705873f39156375bbbbd6d90979d6fa78b7479f10508b21d6e

.github/workflows/build.yml

@@ -91,19 +91,24 @@ jobs:
           ref: ${{ github.event.pull_request.head.sha }}
 
 
+      - name: Cache depends sources
+        uses: actions/cache@v4
+        with:
+          path: |
+            depends/sources
+          key: depends-sources-${{ hashFiles('depends/packages/*') }}
+          restore-keys: |
+            depends-sources-
+
       - name: Cache dependencies
         uses: actions/cache@v4
         with:
           path: |
-            depends/built
             depends/${{ matrix.host }}
-            depends/sdk-sources
-          # We don't care about no specific key as depends system will handle that for us
-          key: ${{ runner.os }}-depends-${{ matrix.host }}-${{ github.sha }}
+          key: ${{ runner.os }}-depends-${{ matrix.build_target }}-${{ hashFiles('depends/packages/*') }}
           restore-keys: |
-            ${{ runner.os }}-depends-${{ matrix.host }}-${{ github.sha }}
-            ${{ runner.os }}-depends-${{ matrix.host }}
-            ${{ runner.os }}-depends
+            ${{ runner.os }}-depends-${{ matrix.build_target }}-${{ hashFiles('depends/packages/*') }}
+            ${{ runner.os }}-depends-${{ matrix.build_target }}
 
       - name: Build dependencies
         run: make -j$(nproc) -C depends HOST=${{ matrix.host }}
@@ -146,26 +151,27 @@ jobs:
         uses: actions/cache/restore@v4
         with:
           path: |
-            depends/built
             depends/${{ matrix.host }}
-            depends/sdk-sources
-          # We don't care about no specific key as depends system will handle that for us
-          key: ${{ runner.os }}-depends-${{ matrix.host }}-${{ github.sha }}
+          key: ${{ runner.os }}-depends-${{ matrix.build_target }}-${{ hashFiles('depends/packages/*') }}
           restore-keys: |
-            ${{ runner.os }}-depends-${{ matrix.host }}-${{ github.sha }}
-            ${{ runner.os }}-depends-${{ matrix.host }}
-            ${{ runner.os }}-depends
+            ${{ runner.os }}-depends-${{ matrix.build_target }}-${{ hashFiles('depends/packages/*') }}
+            ${{ runner.os }}-depends-${{ matrix.build_target }}
+
+      - name: Determine PR Base SHA
+        id: vars
+        run: |
+          echo "PR_BASE_SHA=${{ github.event.pull_request.base.sha || '' }}" >> $GITHUB_OUTPUT
 
       - name: CCache
         uses: actions/cache@v4
         with:
           path: |
             /cache
-          key: ${{ runner.os }}-${{ matrix.host }}-${{ github.sha }}
+          key: ${{ runner.os }}-${{ matrix.build_target }}-${{ github.sha }}
           restore-keys: |
-            ${{ runner.os }}-${{ matrix.host }}-${{ github.sha }}
-            ${{ runner.os }}-${{ matrix.host }}
-            ${{ runner.os }}
+            ${{ runner.os }}-${{ matrix.build_target }}-${{ github.sha }}
+            ${{ runner.os }}-${{ matrix.build_target }}-${{ steps.vars.outputs.PR_BASE_SHA }}
+            ${{ runner.os }}-${{ matrix.build_target }}
 
       - name: Build source and run tests
         run: |

.github/workflows/guix-build.yml

@@ -79,6 +79,14 @@ jobs:
           path: dash
           fetch-depth: 0
 
+      - name: Cache depends sources
+        uses: actions/cache@v4
+        with:
+          path: dash/depends/sources
+          key: depends-sources-${{ hashFiles('dash/depends/packages/*') }}
+          restore-keys: |
+            depends-sources-
+
       - name: Cache Guix and depends
         id: guix-cache-restore
         uses: actions/cache@v3
@@ -86,7 +94,6 @@ jobs:
           path: |
             ${{ github.workspace }}/.cache
             ${{ github.workspace }}/dash/depends/built
-            ${{ github.workspace }}/dash/depends/sources
             ${{ github.workspace }}/dash/depends/work
             /gnu/store
           key: ${{ runner.os }}-guix-${{ matrix.build_target }}-${{ github.sha }}