this derivation will be built:
  /nix/store/jamqrpkjdmnm0zxd3c96pkjhqggkd53r-interpolate-conformance.drv
bld4: building jamqrpkjdmnm0zxd3c96pkjhqggkd53r-interpolate-conformance.drv
10 cases: Nix interpolate == Python interpolate == expected