@Ericson2314, thanks for your PR! By analyzing the history of the files in this pull request, we identified @edolstra, @copumpkin and @jwiegley to be potential reviewers.

Well, this one is uncharacteristically small an readable :).

IMHO we went in the wrong direction, we should have stopped (and should stop) exporting AR, AS, LD etc. [1] (everything but CC [2]) for cross rather than start exporting them for native, and provide the cross utilities under unprefixed names in the PATH instead. This would have avoided (and will avoid) much debugging and unnecessary workarounds against upstream build scripts, both for native and for cross packaging [3].

[1] This does not apply to BUILD_{var} and {var}_FOR_BUILD.
[2] CC is used consistently upstream and it smooths the difference between gcc and clang.
[3] For example ed will just build, without #32489.

@orivej my original goal was to end up always prefixing all tools with their target platforms (wrapper script only for multi-platform tools). I think the current design makes more sense with that objective.

Yours probably would be epitomized with instead prefixing the binaries with build- and target-, which would also work, and avoid a lot of the of the add-flags.sh and role craziness. But it would mean that buildPackages.buidlPackges.my_compiler (e.g. buildPackages.stdenv.cc) would not work.