Thu Oct 31 11:45:48 EDT 2019

revisit basics -- nix-build FAQ

1. The builder attribute points to a script that is executed with
   bash.  It does not seem to have PATH variable set.  Why?

2. The builder script has almost nothing in its enviroment except for
   a couple of variables that can be made to point to components.  So
   any explicit builder script is a good reference point to see how a
   build environment is set up.