When specifying main manually, this will suffice:

1test_deps = _deps + dependency('Catch2')

Which will pick up the pkgconfig configuration typically. However, to use the main which comes with catch2 it is easier to use cmake:

1test_deps += dependency(
2  'Catch2',
3  method: 'cmake',
4  modules: ['Catch2::Catch2WithMain'],
5)

The rest of the tests can be setup via auto-discovery as discussed before.