this derivation will be built:
  /nix/store/srrjh80knp7vmn76prb8lfvdfbxi0k8g-interpolate-conformance.drv
bld3: building srrjh80knp7vmn76prb8lfvdfbxi0k8g-interpolate-conformance.drv
10 cases: Nix interpolate == Python interpolate == expected