[staging] stdenv: gcc_11 → gcc_12

[fabianhjr]

Description of changes

This changes the default gcc version from gcc11 to gcc12

Things done

Depends on #206805

Pending:

• custom jobset in hydra to detect other issue?
  https://hydra.nixos.org/jobset/nixpkgs/pr-206907-gcc12

Tested with GNOME/GDM NixOS (about 4k-6k builds?)

Checklist:

• 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, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.05 Release Notes (or backporting 22.11 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
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[fabianhjr]

Been using these changes for a while now:

Linux version 6.0.13-hardened1 (nixbld@localhost) (gcc (GCC) 12.2.0, GNU ld (GNU Binutils) 2.39) #1-NixOS SMP PREEMPT_DYNAMIC Wed Dec 14 10:41:06 UTC 2022

Haven't noticed any issues

[vcunat]

Jobset: https://hydra.nixos.org/jobset/nixpkgs/pr-206907-gcc12

For now just x86_64-linux with low priority. It's likely to advance a lot while staging-next-* waits for *-darwin to catch up, but we'll see.

[vcunat]

By looking at this the upgrade might go relatively easily: https://gcc.gnu.org/gcc-12/porting_to.html

[ghost]

Would you mind rebasing this to latest origin/staging? It makes it easier for me to test that #209870 still works regardless of whether it or this merges first.

[vcunat]

It's intentionally based on recent master to avoid mixing up with (potential) regressions from master..staging. This makes comparisons easier, e.g. now https://hydra.nixos.org/eval/1789845?compare=1789809

[fabianhjr]

Doing so would also cause a mass rebuild on hydra.

Not sure I should do that resource-wise.

[vcunat]

Right, the rebuild on Hydra would seem wasteful to me at this point.

[trofi]

Bisect says cb57273 stdenv: gcc_11 → gcc_12 broke dmd test on master:

$ nix build -f. -L dmd
...
Test 'runnable_cxx/cppa.d' failed. The logged output:
g++ -m64 -c runnable_cxx/extra-files/cppb.cpp -o test_results/runnable_cxx/cppb.cpp.o -std=c++11
/build/dmd/generated/linux/release/64/dmd -conf= -m64 -Irunnable_cxx -checkaction=C  -fPIC -L-lstdc++
 -L--no-demangle  -odtest_results/runnable_cxx -oftest_results/runnable_cxx/cppa_0  runnable_cxx/cppa
.d test_results/runnable_cxx/cppb.cpp.o
/nix/store/0n4dckknrk1fyvh858hyqv9bk3nhn67s-binutils-2.39/bin/ld: test_results/runnable_cxx/cppa_0.o:
 in function `_ZNSaIiE10deallocateEPim':
runnable_cxx/cppa.d:(.text._ZNSaIiE10deallocateEPim[_ZNSaIiE10deallocateEPim]+0x5): undefined referen
ce to `_ZN9__gnu_cxx13new_allocatorIiE10deallocateEPim'
collect2: error: ld returned 1 exit status
Error: linker exited with status 1
...
FAILED targets:
- runnable_cxx/cppa.d