libdnf: switch back to default stdenv.

[rb2k]

Motivation for this change

The only reason this was on GCC was because of some implicit constructor conversion issues that gcc handled without complaining and clang did not.

This commit fixed those:
rpm-software-management/libdnf@fefe0b6

Now that it works on clang, might as well revert back to the default.

Note: I can't currently test this on darwin because libbfd in master seem broken even without my modifications. I just end up with this: https://www.internalfb.com/phabricator/paste/view/P459437194

I did however apply the fefe0b69e8368a8e9ceeed107add174c64f00f5e commit as a patch to 21.05 and was able to also compile it with stdenv.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• 21.11 Release Notes (or backporting 21.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[alyssais]

This commit message is misleading — what this change does is switch back to the default stdenv, which on most platforms is the gcc stdenv, not the clang one. Could you rephrase it?

[rb2k]

This commit message is misleading — what this change does is switch back to the default stdenv, which on most platforms is the gcc stdenv, not the clang one. Could you rephrase it?

Yeah, you're right. That's better. PR is still in draft form and not quite ready, so I'll add some more details over the next few minutes :)

[rb2k]

Result of nixpkgs-review pr 138540 run on x86_64-linux 1

2 packages built:

• libdnf
• microdnf

[alyssais]

The commit message still doesn't make sense — the version you changed the PR title to is good, can you use that as the commit message too?

[rb2k]

The commit message still doesn't make sense — the version you changed the PR title to is good, can you use that as the commit message too?

ugh, sorry. clearly I need more coffee this morning :)
done

[alyssais]

@ofborg build libdnf.override { stdenv = clangStdenv; }

[alyssais]

Hmm, that appeared not to work. Can I get it to work like this?

@ofborg build libdnf.override{stdenv=clangStdenv;}

[rb2k]

Found the issue with darwin on master: #138545 (indeed unrelated to this)

[alyssais]

Tested on x86_64-linux with

nix-build -E 'with import <nixpkgs> {}; libdnf.override { stdenv = clangStdenv; }' -I nixpkgs=https://github.com/NixOS/nixpkgs/tarball/pull/138540/head