movefasta/nixpkgs
1
0
Fork 0
mirror of https://github.com/NixOS/nixpkgs.git synced 2025-06-09 19:13:26 +03:00
Code Issues Projects Releases Packages Wiki Activity

document Import From Derivation (IFD) policy

Browse source
This commit is contained in:
Valentin Gagarin 2022-12-05 16:24:52 +01:00
parent 5b9b93b9be
commit 53b5a47c12
2 changed files with 16 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

15
doc/contributing/coding-conventions.chapter.md
View file

@ -670,3 +670,18 @@ stdenv.mkDerivation {
...
}
```
### Import From Derivation {#ssec-import-from-derivation}
Import From Derivation (IFD) is disallowed in Nixpkgs for performance reasons:
[Hydra] evaluates the entire package set, and sequential builds during evalation would increase evaluation times to become impractical.
[Hydra]: https://github.com/NixOS/hydra
Import From Derivation can be worked around in some cases by committing generated intermediate files to version control and reading those instead.
<!-- TODO: remove the following and link to Nix manual once https://github.com/NixOS/nix/pull/7332 is merged -->
See also [NixOS Wiki: Import From Derivation].
[NixOS Wiki: Import From Derivation]: https://nixos.wiki/wiki/Import_From_Derivation