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Diffstat (limited to 'doc/languages-frameworks/pkg-config.section.md')
-rw-r--r-- | doc/languages-frameworks/pkg-config.section.md | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/doc/languages-frameworks/pkg-config.section.md b/doc/languages-frameworks/pkg-config.section.md index ee0a471be3e57..eecc84b4c1aae 100644 --- a/doc/languages-frameworks/pkg-config.section.md +++ b/doc/languages-frameworks/pkg-config.section.md @@ -4,6 +4,48 @@ Nixpkgs provides a couple of facilities for working with this tool. - - A [setup hook](#setup-hook-pkg-config) bundled with in the `pkg-config` package, to bring a derivation's declared build inputs into the environment. - - The [`validatePkgConfig` setup hook](https://nixos.org/manual/nixpkgs/stable/#validatepkgconfig), for packages that provide pkg-config modules. - - The `defaultPkgConfigPackages` package set: a set of aliases, named after the modules they provide. This is meant to be used by language-to-nix integrations. Hand-written packages should use the normal Nixpkgs attribute name instead. +## Writing packages providing pkg-config modules + +Packages should set `meta.pkgConfigProvides` with the list of package config modules they provide. +They should also use `testers.testMetaPkgConfig` to check that the final built package matches that list. +Additionally, the [`validatePkgConfig` setup hook](https://nixos.org/manual/nixpkgs/stable/#validatepkgconfig), will do extra checks on to-be-installed pkg-config modules. + +A good example of all these things is zlib: + +``` +{ pkg-config, testers, ... }: + +stdenv.mkDerivation (finalAttrs: { + ... + + nativeBuildInputs = [ pkg-config validatePkgConfig ]; + + passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage; + + meta = { + ... + pkgConfigModules = [ "zlib" ]; + }; +}) +``` + +## Accessing packages via pkg-config module name + +### Within Nixpkgs + +A [setup hook](#setup-hook-pkg-config) is bundled in the `pkg-config` package to bring a derivation's declared build inputs into the environment. +This will populate environment variables like `PKG_CONFIG_PATH`, `PKG_CONFIG_PATH_FOR_BUILD`, and `PKG_CONFIG_PATH_HOST` based on: + + - how `pkg-config` itself is depended upon + + - how other dependencies are depended upon + +For more details see the section on [specifying dependencies in general](#ssec-stdenv-dependencies). + +Normal pkg-config commands to look up dependencies by name will then work with those environment variables defined by the hook. + +### Externally + +The `defaultPkgConfigPackages` package set is a set of aliases, named after the modules they provide. +This is meant to be used by language-to-nix integrations. +Hand-written packages should use the normal Nixpkgs attribute name instead. |