ci: fix SCCACHE_DIR expansion and use OS-specific default; cache the correct dir; guard mkdir; avoid literal /Users/zemaj in env

.github/workflows/release.yml

@@ -143,11 +143,28 @@ jobs:
           core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
           core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
 
+    # Compute a writable sccache directory per-OS and export to env
+    - name: Set sccache dir
+      shell: bash
+      run: |
+        case "${{ runner.os }}" in
+          macOS)
+            echo "SCCACHE_DIR=$HOME/Library/Caches/Mozilla.sccache" >> "$GITHUB_ENV"
+            ;;
+          Linux)
+            echo "SCCACHE_DIR=$HOME/.cache/sccache" >> "$GITHUB_ENV"
+            ;;
+          *)
+            # Use sccache default on Windows; no override
+            ;;
+        esac
+
     # Persist local sccache directory as a fallback/shared cache
     - name: Cache sccache directory (fallback)
       uses: actions/cache@v4
+      if: runner.os != 'Windows'
       with:
-        path: ~/.cache/sccache
+        path: ${{ env.SCCACHE_DIR }}
         key: sccache-${{ runner.os }}-${{ matrix.target }}-rust-1.89.0-${{ hashFiles('codex-rs/Cargo.lock') }}
         restore-keys: |
           sccache-${{ runner.os }}-${{ matrix.target }}-rust-1.89.0-
@@ -215,8 +232,6 @@ jobs:
         SCCACHE_GHA_ENABLED: 'true'
         # Avoid hard-fail if sccache server has IO error; prefer fallback
         SCCACHE_IGNORE_SERVER_IO_ERROR: '1'
-        # Use a consistent local cache directory across OSes for fallback and caching
-        SCCACHE_DIR: $HOME/.cache/sccache
         # Show more detail on failures
         RUST_BACKTRACE: "1"
       run: |
@@ -230,7 +245,9 @@ jobs:
           if ! sccache --start-server; then
             echo "sccache GHA backend failed to start; falling back to local disk cache"
             unset SCCACHE_GHA_ENABLED
-            mkdir -p "$SCCACHE_DIR"
+            if [ -n "${SCCACHE_DIR:-}" ]; then
+              mkdir -p "$SCCACHE_DIR"
+            fi
             if ! sccache --start-server; then
               echo "sccache local cache also failed; disabling sccache"
               unset RUSTC_WRAPPER