Re: [PATCH] gnu: cross-libc: Cross build the correct libc for GNU/Hurd systems.

[Ludovic Courtès]

Hi!

Manolis Ragkousis <address@hidden> skribis:

> The previous version of my patch was not using target to correctly
> determine which glibc to inherit. It was using %current-target-system
> which caused me many problems.
>
> With this version I modified it to use cross-libc-for-target so there
> will not be any problems in case %current-target-system is not set.

“Problems” is a bit vague, but I’m glad you’ve overcome them.  :-)

> From 92689506f1969ac67631f77024511a5c96f341e8 Mon Sep 17 00:00:00 2001
> From: Manolis Ragkousis <address@hidden>
> Date: Wed, 8 Jun 2016 17:15:00 +0300
> Subject: [PATCH] gnu: cross-libc: Cross build the correct libc for GNU/Hurd
>  systems.
>
> * gnu/packages/cross-base.scm (cross-libc): Add xgnumach-headers, xmig,
>   xhurd-headers, xglibc/hurd-headers, xhurd-minimal, xhurd-core-headers,
>   cross-kernel-headers and cross-libc-for-target.  Use "cross-libc-for-target"
>   to determine the correct libc to use.
>   [arguments]: Set "CROSS_LIBRARY_PATH".
>   [propagated-inputs]: Use "cross-kernel-headers" to determine the correct 
> headers.
>   [native-inputs]: Use "cross-mig" when target is GNU/Hurd.

[...]

> +  (define (cross-kernel-headers target)
> +    "Return headers depending on TARGET."
> +    (match target
> +      ((or "i586-pc-gnu" "i586-gnu") xhurd-core-headers)
> +      (_ xlinux-headers)))

Could you move this procedure, as well as xgnumach-headers and co., to
the top level?  That way there’d be less “clutter” in the definition of
‘cross-libc’ itself.  WDYT?

Other than that it LGTM, but if, and only if, you can verify that this
does not cause any regression for other cross-compilation targets.
Normally this should not change derivations at all so you don’t even
need to build them.  Just run this:

  ./pre-inst-env guix build gcc --target=mips64el-linux-gnu -d

both before and after the change, and the result should be the same .drv
file name.

Thanks!

Ludo’.