Nikita Karetnikov <nik...@karetnikov.org> skribis: >> I realize this is a bit more involved than “just” packaging the thing, >> but it will be useful in the long run. > > I'm missing the big picture. That's the main problem. What will happen > when I run 'guix-package -i hello'?
‘build-system’ objects are an abstraction over the underlying build system. A build system is basically couple of procedures: one to perform a native build, and one to perform a cross-build (which is not implemented yet.) The ‘package-derivation’ procedure takes a package and return its derivation (see the manual.) To do that, it actually invokes the build procedure of the package’s build system. When it’s ‘gnu-build-system’, the build procedure is ‘gnu-build’ from the (guix build-system gnu) package. In turn, this ‘gnu-build’ creates a build script that invokes the build-side ‘gnu-build’–the one from (guix build gnu-build-system). And from there, you see what happens. (See the manual about “strata”.) If you want all the details, you can try this: --8<---------------cut here---------------start------------->8--- scheme@(guile-user)> (use-modules (guix store) (guix derivations) (guix packages) (gnu packages base)) scheme@(guile-user)> (define s (open-connection)) scheme@(guile-user)> ,trace (package-derivation s guile-final) --8<---------------cut here---------------end--------------->8--- Beware, it produces a *lot* of output. > Let's assume that I'll do the same in 'python-build-system.scm'. Can I > reuse 'set-paths' and 'unpack'? Should I write my own functions > instead? You would probably reuse them, yes. So (guix build python-build-system) would most likely #:use-module (guix build gnu-build-system), to facilitate that. > How can I determine what environment variables and prefixes should be > used? You at least need $PATH and $PYTHONPATH, perhaps $LD_LIBRARY_PATH too. > I've noticed that 'development/python-modules/generic/default.nix' uses > 'easy_install'. Should we use it? Probably, though you’d rather ask a Pythoner to check whether this is still the recommended way. Ludo’.
