nix_fetchers_dep,

        '-DNIX_IS_@0@'.format(nix_impl.to_upper()),

option('nix_impl', type: 'combo', choices: ['', 'cppnix', 'lix'])

        'werror': true,

nix_impl = get_option('nix_impl')

nix_main_dep = dependency('nix-main', required: true)
nix_store_dep = dependency('nix-store', required: true)

nix_main_dep_names = {
    'cppnix': 'nix-main',
    'lix': 'lix-main',
}
if nix_impl != ''
    nix_main_dep = dependency(nix_main_dep_names.get(nix_impl))
else
    nix_main_dep = dependency('', required: false)
    foreach impl, dep_name : nix_main_dep_names
        d = dependency(dep_name, required: false)
        if d.found() and nix_main_dep.found()
            error('Both cppnix and lix are installed, choose one with -Dnix_impl=')
        endif
        nix_main_dep = d
        nix_impl = impl
    endforeach
    if not d.found()
        error('No Nix implementation found')
    endif
endif
nix_store_dep_names = {
    'cppnix': 'nix-store',
    'lix': 'lix-store',
}
nix_store_dep = dependency(nix_store_dep_names.get(nix_impl))

nix_fetchers_dep_names = {
    'cppnix': 'nix-fetchers',
    'lix': 'lix-fetchers',
}
nix_fetchers_dep = dependency(nix_fetchers_dep_names.get(nix_impl))