Cross compilation from x86_64 to x86_64 with custom gcc arch/tune fails #268767
Description
Steps to reproduce
I have small VPS which could benefit greatly from AES-NI and other fancy instructions. It can't be used for building due to load limitations, so I've attempted to do compilation on local machine and push that on remote target:
nixos-rebuild --flake .#myServer \
--target-host servername \
--build-host localhost \
bootWiki suggest tweaking configuration for such scenario in this way:
nixpkgs = {
# building ON
localSystem = {
system = "x86_64-linux";
};
# building FOR
crossSystem = {
gcc.arch = "znver2";
gcc.tune = "znver2";
system = "x86_64-linux";
};
};However it fails while trying to compile bash:
checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
Beginning configuration for bash-5.2-release for x86_64-unknown-linux-gnu
checking for x86_64-unknown-linux-gnu-gcc... x86_64-unknown-linux-gnu-gcc
checking whether the C compiler works... no
configure: error: in `/build/bash-5.2':
configure: error: C compiler cannot create executables
After that I've tried alternative approach that doesn't touch localSystem / crossSystem and modifies compiler wrapper instead:
crossOverlays = [
(final: prev: {
wrapCC = cc: prev.wrapCCWith {
inherit cc;
extraBuildCommands = ''
echo "-O3 -march=znver2 -mtune=znver2" >> "$out/nix-support/cc-cflags"
'';
};
})
];Sadly that failed on python (bash worked though):
Found duplicated packages in closure for dependency 'setuptools':
setuptools 68.2.2.post0 (/nix/store/rk7kwr8c0v8dwk64442q8c0lp7car7qn-python3.11...
setuptools 68.2.2.post0 (/nix/store/y8yq448xka665bqyd5gvdhajqdbsnyys-python3.11...
Notify maintainers
I've seen @amjoseph-nixpkgs working on cross compilation a lot, I assume it's his area of expertise
Metadata
[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
- system: `"x86_64-linux"`
- host os: `Linux 6.1.62, NixOS, 23.11 (Tapir), 23.11.20231117.c757e9b`
- multi-user?: `yes`
- sandbox: `yes`
- version: `nix-env (Nix) 2.18.1`
- channels(root): `""`
- nixpkgs: `/nix/store/rj6pqzx66pliiwdfk2wjnnlk40rm3mpd-source`