xentools418 build fails, fix

[Greg Troxel <gdt%lexort.com@localhost>]

The problem seems to be

  I have qemu on the system, and hence SDL2.

  xentools418 is set up for not depending on SDL2.

  The build system in tools/qemu-xen finds it:
    sdl2-config found: YES (/usr/pkg/bin/sdl2-config) 2.28.5
    Run-time dependency sdl2 found: YES 2.28.5
    Run-time dependency sdl2_image found: NO (tried pkgconfig)

  This build system is meson not autoconf, and there is no apparent
  support for --without-SDL2.

and I have worked around this by

  --- work/xen-d75f1e9/tools/qemu-xen/meson/mesonbuild/dependencies/ui.py.~1~     2022-06-02 07:40:57.000000000 -0400
  +++ work/xen-d75f1e9/tools/qemu-xen/meson/mesonbuild/dependencies/ui.py 2023-12-30 15:04:32.293450532 -0500
  @@ -132,8 +132,8 @@

   class SDL2DependencyConfigTool(ConfigToolDependency):

  -    tools = ['sdl2-config']
  -    tool_name = 'sdl2-config'
  +    tools = ['sdl2-config-FAIL']
  +    tool_name = 'sdl2-config-FAIL'

       def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
           super().__init__(name, environment, kwargs)

which lets the build go vastly further.


It seems clear this will not break the case where sdl2-config does not
exist.  I view it as the logical equivalent of --without-SDL2, which is
something I'd add without posting.

Assuming the build succeed, I plan to add this as a patch, unless
someone can tell me why I'm confused or what we should do instead.