[Nix-dev] Debugging nixpkgs

[Konrad Hinsen]

While trying to build some derivations for MacOSX, I hit a problem
which I think is a bug in nixpkgs and which moreover I think I know
how to fix. How would I best go about debugging this? Can I just
copy the source code somewhere, modify some files, and then test-build
and test-run with that modified version? Do I risk messing up my
installation that way? I don't quite see yet how modifying the
source code of nixpkgs fits into the "nothing ever changes" view
of Nix.

BTW, the bug I try to fix is in
build-support/native-darwin-cctools-wrapper/builder.sh.  The list of
tools that are linked to the profile should be extended by "lipo",
which is required to build gfortran under MacOSX.

Konrad.