ci: provide usage hint for rust-cache (#31)

.github/actions/basics/action.yml

@@ -24,14 +24,6 @@ runs:
 
     # ===============================================
 
-    - uses: Swatinem/rust-cache@v2
-
-    - uses: ./.github/actions/elapsed-time
-      with:
-        statement: "rust-cache"
-
-    # ===============================================
-
     - uses: cargo-bins/cargo-binstall@main
 
     # ===============================================
@@ -42,40 +34,6 @@ runs:
         cargo binstall --no-confirm lychee prefligit ripgrep
         cargo binstall --no-confirm --locked taplo-cli
 
-    - name: Debug installed binaries
-      shell: bash
-      run: |
-        echo "PATH is: $PATH"
-        echo "CARGO_HOME is: $CARGO_HOME"
-
-        echo
-        echo "==== Searching each PATH directory for 'prefligit' or 'rg' ===="
-        IFS=':' read -ra PATH_ARRAY <<< "$PATH"
-        for dir in "${PATH_ARRAY[@]}"; do
-          echo "-> Checking $dir"
-          # Only list if directory actually exists (some paths may not exist)
-          if [ -d "$dir" ]; then
-            ls -1 "$dir" | grep -E '^(prefligit|rg)$' || true
-          else
-            echo "   (Not a directory)"
-          fi
-        done
-
-        echo
-        echo "==== Checking 'which' output for 'prefligit' or 'rg' ===="
-        which prefligit || echo "'prefligit' not found by 'which'"
-        which rg || echo "'rg' not found by 'which'"
-
-        echo
-        echo "==== Brute-force searching /home/runner for 'prefligit' and 'rg' ===="
-        # Use 'find' instead of 'rg', since 'rg' is missing
-        echo "Searching for prefligit..."
-        find /home/runner -name prefligit 2>/dev/null || echo "No prefligit found."
-
-        echo
-        echo "Searching for rg..."
-        find /home/runner -name rg 2>/dev/null || echo "No rg found."
-
     - uses: ./.github/actions/elapsed-time
       with:
         statement: "install lychee prefligit ripgrep taplo-cli"
@@ -93,6 +51,27 @@ runs:
 
     # ===============================================
 
+    ### rust-cache ###
+    # a)  save all contents even after its action location
+    #
+    # b)  doesn’t cache binaries, but the related metadata will,
+    #     so caused issues like “cargo binstall” detect binaries
+    #     are installed, but actually they don’t exist! These 
+    #     binary installations should be put BEFORE this 
+    #     rust-cache action
+    #
+    # c)  doesn’t remove user's bin files, the "Any files in
+    #     ~/.cargo/bin that were present before the action 
+    #     ran (for example rustc)." says the cache itself
+
+    - uses: Swatinem/rust-cache@v2
+
+    - uses: ./.github/actions/elapsed-time
+      with:
+        statement: "rust-cache"
+
+    # ===============================================
+
     - name: restore lychee cache
       uses: actions/cache@v4
       with: