fix: add debug option for SSH remote shell wrapper to assist with troubleshooting

action.yml

@@ -35,6 +35,10 @@ inputs:
     description: 'Shell to use on remote server (bash, sh, zsh, etc.)'
     required: false
     default: 'bash'
+  debug-shell-wrapper:
+    description: 'Enable debug logging in the SSH remote wrapper (prints script path and contents)'
+    required: false
+    default: 'false'
 
 outputs:
   ssh-config-path:
@@ -212,10 +216,21 @@ runs:
         # Use BatchMode to prevent interactive prompts
         # ConnectTimeout to fail fast if connection issues
         echo "Executing script on remote server '${{ inputs.ssh-host }}' via SSH..."
+        # Print some debug information if requested. See 'debug-shell-wrapper' input.
+        if [ "${SSH_REMOTE_DEBUG-}" = "true" ]; then
+          echo "[ssh-remote wrapper] Script file: $SCRIPT_FILE"
+          echo "[ssh-remote wrapper] Script contents:" >&2
+          sed -n '1,200p' "$SCRIPT_FILE"
+          echo "[ssh-remote wrapper] ---------- end script ----------"
+        fi
         ssh -o BatchMode=yes \
             -o ConnectTimeout=10 \
             github-action-host \
             "${{ inputs.remote-shell }} -s" < "$SCRIPT_FILE"
+        SSH_EXIT_CODE=$?
+        if [ "${SSH_REMOTE_DEBUG-}" = "true" ]; then
+          echo "[ssh-remote wrapper] SSH exit code: $SSH_EXIT_CODE"
+        fi
         WRAPPER_EOF
         
         chmod +x "$WRAPPER_PATH"
@@ -223,12 +238,12 @@ runs:
         # We also create symlink without the .sh extension to provide a
         # short executable name inside the wrapper dir (e.g. $WRAPPER_DIR/ssh-remote)
         ln -s "$WRAPPER_PATH" "$WRAPPER_DIR/ssh-remote"
-        if [ "${{ inputs.use-shell-wrapper }}" = "true" ]; then
-          echo ""
-          echo "To use the remote shell in subsequent steps, add:"
-          echo "  shell: ssh-remote {0}"
-          echo ""
-          echo "The 'ssh-remote' shell is now available for use."
+        if [ "${{ inputs.debug-shell-wrapper }}" = "true" ]; then
+          # Persist debug flag to the job environment; the wrapper can pick
+          # this up later when the job runs. This allows debugging without
+          # changing the wrapper script at runtime.
+          echo "SSH_REMOTE_DEBUG=true" >> $GITHUB_ENV
+          echo "⚠️ SSH remote shell wrapper debug is enabled (SSH_REMOTE_DEBUG=true)"
         fi
         echo "shell-wrapper-dir=$WRAPPER_DIR" >> $GITHUB_OUTPUT
         echo "shell-wrapper-path=$WRAPPER_PATH" >> $GITHUB_OUTPUT
@@ -243,3 +258,8 @@ runs:
         echo "Adding custom shell 'ssh-remote' to PATH"
         echo "PATH=$SHELL_WRAPPER_DIR:$PATH" >> $GITHUB_ENV
         echo "✅ Custom shell 'ssh-remote' registered for this job"
+        echo ""
+        echo "To use the remote shell in subsequent steps, add:"
+        echo "  shell: ssh-remote {0}"
+        echo ""
+        echo "The 'ssh-remote' shell is now available for use."