[Buildroot] [PATCH] package/mesa3d: override dri path

[Romain Naour <romain.naour@gmail.com>]

Since the bump to 1.5.3, pkgconf prepends the sysroot to all absolute
paths found in the .pc file. This is correct when the paths refer to
something in STAGING_DIR (e.g. libdir, includedir), but not when it
refers to something used for the target.

As reported by #11591, the xerver fail to load dri modules (r600_dri.so):

From Xorg.0.log:
(EE) AIGLX error: dlopen of /full/path/to/sysroot/usr/lib/dri/r600_dri.so failed (/full/path/to/sysroot/usr/lib/dri/r600_dri.so: cannot open shared object file: No such file or directory)
(II) GLX: no usable GL providers found for screen 0

That's because the xserver hardcode the dri divers directory path in
DRI_DRIVER_PATH which come from
dridriverdir=`$PKG_CONFIG --variable=dridriverdir dri`

We can see in dri.pc that dridriverdir use libdir which is now prefixed
by the sysroot by pkgconf 1.5.3:

prefix=/usr
exec_prefix=/usr
libdir=${exec_prefix}/lib
includedir=${prefix}/include
dridriverdir=${libdir}/dri

Since we can't rely on pkgconf anymore, use --with-dri-driverdir="/usr/lib/dri"
to use explicitly "/usr/lib/dri" instead of relying on dri.pc.

Tested using TestGlxinfo test from:
http://patchwork.ozlabs.org/patch/1021669/

Fixes:
https://bugs.buildroot.org/show_bug.cgi?id=11591

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
---
 package/mesa3d/mesa3d.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package/mesa3d/mesa3d.mk b/package/mesa3d/mesa3d.mk
index 2fe46bdd8b..becc286361 100644
--- a/package/mesa3d/mesa3d.mk
+++ b/package/mesa3d/mesa3d.mk
@@ -136,6 +136,7 @@ endif
 MESA3D_CONF_OPTS += \
 	--enable-shared-glapi \
 	--enable-driglx-direct \
+	--with-dri-driverdir="/usr/lib/dri" \
 	--with-dri-drivers=$(subst $(space),$(comma),$(MESA3D_DRI_DRIVERS-y))
 endif
 
-- 
2.14.5