Print an error and exit if 'rust-src-dir' does not point to an existing directory

action.yml

@@ -171,6 +171,10 @@ runs:
       run: |
         if [[ -d "$rust_src_dir" ]]; then
           cd "$rust_src_dir"
+        else
+          echo "'rust-src-dir' does not point to an existing directory" >&2
+          echo "The value of 'rust-src-dir' is: ${rust_src_dir}" >&2
+          exit 1
         fi
         if [[ -z "$toolchain" && ( -f "rust-toolchain" || -f "rust-toolchain.toml") ]]
         then
@@ -201,7 +205,12 @@ runs:
     - id: versions
       name: Print installed versions
       shell: bash
+      env:
+        rust_src_dir: ${{inputs.rust-src-dir}}
       run: |
+        # Switch to the selected sub-directory for
+        cd "$rust_src_dir"
+
         echo "rustc-version=$(rustc --version)" >> $GITHUB_OUTPUT
         rustc --version --verbose
         echo "cargo-version=$(cargo --version)" >> $GITHUB_OUTPUT