Add support for xmake build system

Project information:

Name: xmake
License: Apache 2.0
Upstream has been contacted:

I want to build my flatpak app using this build system, which I have installed in my Fedora linux workstation. It works fine, but trying to use it with flatpak-builder fails, because the xmake command cannot be found. My manifest file:

id: com.x_engine.App1
runtime: org.freedesktop.Platform
runtime-version: '23.08'
sdk: org.freedesktop.Sdk
command: app1_linux_x86_64-release

- name: App1
  buildsystem: simple
    # The install prefix must be /app
    - xmake build app1
    - xmake install -o ./app app1
  # builddir: true
    - type: dir
      path: /home/paul/Programming/xmake/X/

  # Wayland access
  - --socket=wayland
  # Show windows using X11, if Wayland is not available,
  # overrides x11 socket permission
  - --socket=fallback-x11
  # share IPC namespace with the host (necessary for X11)
  - --share=ipc
  # OpenGL rendering
  - --device=dri
  # Audio
  - --socket=pulseaudio

  - xmake f -c

I’ve tried to write the build commands into a shell script file and calling that file in the build-commands section, but it also cannot find the xmake executable

It seems I cannot edit the thread for some reason. I have posted in the official github for the xmake project