29a2c82603
Without the change the eval fails as:
$ nix build --no-link -f. pythonInterpreters.pypy39_prebuilt.buildEnv
error:
error: attribute 'pypy38_prebuilt' missing
208| # Not included at top-level
209| self = __splicedPackages.pythonInterpreters.pypy38_prebuilt;
| ^
210| sourceVersion = {
Did you mean one of pypy39_prebuilt or pypy27_prebuilt?