this derivation will be built:
  /nix/store/8fszzdwrc64szwwlwzj266jm5s3kh9w9-interpolate-conformance.drv
bld4: building 8fszzdwrc64szwwlwzj266jm5s3kh9w9-interpolate-conformance.drv
10 cases: Nix interpolate == Python interpolate == expected