this derivation will be built:
  /nix/store/widj5hkkrbaxq0mzn0gjawfzx1sj1gr2-interpolate-conformance.drv
bld4: building widj5hkkrbaxq0mzn0gjawfzx1sj1gr2-interpolate-conformance.drv
10 cases: Nix interpolate == Python interpolate == expected