subproject()'s default_options doesn't accept feature options

[lorcap]

With meson 1.6.0, the following statement:

ft = get_option('feature')
subproject('sub', default_options: { 'ft': ft })

results in the following error:

subproject keyword argument 'default_options' was of type dict[UserFeatureOption] but should have been one of: str, array[str], dict[str | int | bool | list]

when feature is a feature option.

It should be possible to pass a feature option value as it happens for string, combo, boolean, and integer (with .to_string()).

[lorcap]

In the meantime, the following workaround can be used:

ft = get_option('feature')

if ft.enabled()
  ft_str = 'enabled'
elif ft.disabled()
  ft_str = 'disabled'
else
  ft_str = 'auto'
endif

subproject('sub', default_options: { 'ft': ft })