meson/test cases/unit/3 subproject defaults/meson_options.txt

option('defopoverride', type : 'string', value : 'optfile', description : 'A value for overriding.')
option('fromcmdline', type : 'string', value : 'optfile', description : 'A value for overriding.')
option('fromoptfile', type : 'string', value : 'optfile', description : 'A value for not overriding.')