try it this way

.github/actions/build-electron/action.yml

@@ -68,21 +68,20 @@ runs:
         export WINEPREFIX="$HOME/.wine"
         mkdir -p "$WINEPREFIX"
         echo "WINEPREFIX=$WINEPREFIX" >> $GITHUB_ENV
-        # Start a persistent Xvfb server for wine (xvfb-run per-invocation hangs
-        # because wineserver keeps the X connection alive)
-        export XDG_RUNTIME_DIR=/tmp/runtime-$(whoami)
-        echo "XDG_RUNTIME_DIR=$XDG_RUNTIME_DIR" >> $GITHUB_ENV
-        mkdir -p "$XDG_RUNTIME_DIR"
-        Xvfb :99 -screen 0 1024x768x24 &
-        export DISPLAY=:99.0
-        echo "DISPLAY=:99.0" >> $GITHUB_ENV
         # Initialize wine prefix to avoid first-run delays during build
         "$WINE_PATH" wineboot --init 2>/dev/null || true
-        "$WINE_PATH" wineboot --update
-        # Pass wine path to GN so siso can find it regardless of PATH
-        GN_APPENDED_ARGS="$GN_EXTRA_ARGS v8_wine_path=\"$WINE_PATH\""
+        # Create a wrapper script so v8_wine_path is a single path without spaces
+        # (GN_EXTRA_ARGS is split on spaces, so a value like "xvfb-run /usr/bin/wine" breaks GN arg parsing)
+        WINE_WRAPPER="/usr/local/bin/xvfb-wine"
+        printf '#!/bin/sh\nxvfb-run %s "$@"\nSTATUS=$?\nwineboot -k\nexit $STATUS\n' "$WINE_PATH" | sudo tee "$WINE_WRAPPER" > /dev/null
+        sudo chmod +x "$WINE_WRAPPER"
+        GN_APPENDED_ARGS="$GN_EXTRA_ARGS v8_wine_path=\"$WINE_WRAPPER\""
         echo "GN_EXTRA_ARGS=$GN_APPENDED_ARGS" >> $GITHUB_ENV
         echo "GN APPENDED_ARGS set with wine path: $GN_APPENDED_ARGS"
+        export XDG_RUNTIME_DIR=/tmp/runtime-$(whoami)
+        mkdir -p "$XDG_RUNTIME_DIR"
+        echo "XDG_RUNTIME_DIR=$XDG_RUNTIME_DIR" >> $GITHUB_ENV
+        echo "DISPLAY=:99.0" >> $GITHUB_ENV
     # - name: Download mksnapshot.zip
     #   shell: bash
     #   if: ${{ inputs.target-platform == 'win' }}