this derivation will be built:
  /nix/store/kinhngc6ay38gznyjm0z95x4zc9g2136-interpolate-conformance.drv
bld4: building kinhngc6ay38gznyjm0z95x4zc9g2136-interpolate-conformance.drv
10 cases: Nix interpolate == Python interpolate == expected