Flake: How to have a Literal Value Input (no URL/file path)

If you have a small set of flags (ie: =< 3 features), you can use different outputs.

packages.x86_64-linux.default = ... # default version
packages.x86_64-linux.f1   = ... # feature1 enabled version
packages.x86_64-linux.f2   = ... # feature2 enabled version
packages.x86_64-linux.f1f2 = ... # feature1 and feature2 enabled version
...

Check this out :smiling_imp: