Bug 607344 – sys-devel/crossdev - impossible to adjust search path for cross-pkg-config

• Product: Gentoo Linux
• Status: RESOLVED NEEDINFO

[Description Coacher 2017-01-26 21:56:58 UTC]

Hello.

crossdev-pkg-config makes cross-compiling against some packages from the tree unnecessarily hard. For example, I'm positive most people who have raspberry-pi want to cross-compile packages for it. media-libs/raspberrypi-userland installs into /opt, including pkgconfig files which go to /opt/vc/lib/pkgconfig.

crossdev-pkg-config nukes PKG_CONFIG_PATH. Fine.
crossdev-pkg-config nukes EXTRA_PKG_CONFIG_LIBDIR. What?

I have seen bug 310807 and sadly it was closed without a proper fix.
Here's a simple test:
(crossdev) ~ # /usr/bin/arm-unknown-linux-gnueabi-pkg-config --cflags bcm_host
Package bcm_host was not found in the pkg-config search path.
Perhaps you should add the directory containing `bcm_host.pc'
to the PKG_CONFIG_PATH environment variable
No package 'bcm_host' found
(crossdev) ~ # PKG_CONFIG_PATH=/usr/arm-unknown-linux-gnueabi/opt/vc/lib/pkgconfig /usr/bin/arm-unknown-linux-gnueabi-pkg-config --cflags bcm_host
Package bcm_host was not found in the pkg-config search path.
Perhaps you should add the directory containing `bcm_host.pc'
to the PKG_CONFIG_PATH environment variable
No package 'bcm_host' found
(crossdev) ~ # EXTRA_PKG_CONFIG_LIBDIR=/usr/arm-unknown-linux-gnueabi/opt/vc/lib/pkgconfig /usr/bin/arm-unknown-linux-gnueabi-pkg-config --cflags bcm_host
Package bcm_host was not found in the pkg-config search path.
Perhaps you should add the directory containing `bcm_host.pc'
to the PKG_CONFIG_PATH environment variable
No package 'bcm_host' found
(crossdev) ~ # PKG_CONFIG_PATH=/usr/arm-unknown-linux-gnueabi/opt/vc/lib/pkgconfig /usr/bin/pkg-config --cflags bcm_host
-DUSE_VCHIQ_ARM -I/opt/vc/include -I/opt/vc/include/interface/vmcs_host/linux -I/opt/vc/include/interface/vcos/pthreads

Please fix.

[Comment 1 Coacher 2017-01-26 22:07:59 UTC]

This is with crossdev-99999999 @ 8b1b79e02cc36bc6f2b5583db6aeea333fb8d59b.

[Comment 2 Coacher 2017-01-27 20:16:00 UTC]

Created attachment 461652 [details, diff]
0001-cross-pkg-config-preserve-EXTRA_PKG_CONFIG_LIBDIR.patch

[Comment 3 Coacher 2017-01-27 20:23:43 UTC]

Here's a git formatted patch that fixes EXTRA_PKG_CONFIG_LIBDIR handling and allows me to successfully cross-compile against media-libs/raspberrypi-userland.

[Comment 4 Sergei Trofimovich (RETIRED) 2018-02-11 16:45:33 UTC]

Tl;DR: I'm not sure EXTRA_PKG_CONFIG_LIBDIR is the correct wa to expose it. Should we allow overriding PKG_CONFIG_PATH instead in a smarter way?

Mike, WDYT?

Long version:

I'm not very familiar with pkg-config ways of looking up packages.

Is PKG_CONFIG_LIBDIR the correct variable to override in general? It sounds like PKG_CONFIG_PATH is what you really need (crossdev also filters PKG_CONFIG_PATH out).

raspberrypi-userland even tries to set PKG_CONFIG_PATH (without ${ROOT})
  etc/env.d/04raspberrypi-userland:PKG_CONFIG_PATH='/opt/vc/lib/pkgconfig'
but there is no way to prepend ${ROOT}/${SYSROOT} to it (or is there?)

crossdev does a crude thing:
  etc/portage/make.conf:PKG_CONFIG_PATH="${ROOT}usr/lib/pkgconfig/"
Does it work given the unset in cross-pkg-config?

Only media-video/mpv in ::gentoo tries to attempt to use EXTRA_PKG_CONFIG_LIBDIR and I guess it does not work for years.

I see your change mostly touches uclinux code branch. Do you use it? I'm not sure what uclinux is WRT this code.

Unsetting EXTRA_PKG_CONFIG_LIBDIR was added long ago in https://gitweb.gentoo.org/proj/crossdev.git/commit/wrappers/cross-pkg-config?id=8f6b30809941541bf7389bda55e5c8eb2bdb2b9f

EXTRA_PKG_CONFIG_LIBDIR is crossdev-only wrapper variable, not a pkg-config specific variable. I'm not sure it's a good idea to expose it as an API.

[Comment 5 Sergei Trofimovich (RETIRED) 2019-12-23 00:04:10 UTC]

Perhaps it would help if you post exact steps you want to work:
1. crossdev command to build a ${SYSROOT}
2. cross-emerge command to build a package
3. build log of a failure

Then it should be easier for me to understand what is lacking here.