diff options
| author | Jade Lovelace <lix@jade.fyi> | 2024-05-15 21:40:39 -0700 |
|---|---|---|
| committer | Jade Lovelace <lix@jade.fyi> | 2024-05-15 21:54:12 -0700 |
| commit | 6d84d6bdc1904b1afeecac4ee3fb492966fc882a (patch) | |
| tree | 069463eb33b8f1502d453a6e44cb71b41b445b52 /doc | |
| parent | 7cfaf057e35b7bb329ffff344e30fdfc850566c3 (diff) | |
builtins: fix builtins.langVersion docs to state it's deprecated
This builtin was always a problem and nixpkgs uses it in exactly one
place, to give up if the Nix version is absurdly old. It has no other
use cases, and doesn't work in a multi-implementation world anyway.
Change-Id: I03c36e118591029e2ef14b091fe14a311c66a08a
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual/rl-next/nixversion-fake.md | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/doc/manual/rl-next/nixversion-fake.md b/doc/manual/rl-next/nixversion-fake.md index 93f75611d..725b8e609 100644 --- a/doc/manual/rl-next/nixversion-fake.md +++ b/doc/manual/rl-next/nixversion-fake.md @@ -1,13 +1,17 @@ --- -synopsis: "`builtins.nixVersion` now returns a fixed value \"2.18.3-lix\"" -cls: 558 +synopsis: "`builtins.nixVersion` and `builtins.langVersion` return fixed values" +cls: [558, 1144] credits: jade category: Breaking Changes --- -`builtins.nixVersion` now returns a fixed value `"2.18.3-lix"`. This prevents -feature detection assuming that features that exist in Nix post-Lix-branch-off -might exist, even though the Lix version is greater than the Nix version. +`builtins.nixVersion` now returns a fixed value `"2.18.3-lix"`. + +`builtins.langVersion` returns a fixed value `6`, matching CppNix 2.18. + +This prevents feature detection assuming that features that exist in Nix +post-Lix-branch-off might exist, even though the Lix version is greater than +the Nix version. In the future, check for builtins for feature detection. If a feature cannot be detected by *those* means, please file a Lix bug. |