Well, I wanted to try to check out WebGL on Firefox (v38.0.5 on Linux); and I realized that in
webgl.osmesalib was set to
Graphics -------- Adapter Description: Tungsten Graphics, Inc -- Mesa DRI Intel(R) IGD GEM 20100330 DEVELOPMENT x86/MMX/SSE2 Device ID: Mesa DRI Intel(R) IGD GEM 20100330 DEVELOPMENT x86/MMX/SSE2 Driver Version: 1.4 Mesa 7.10.2 GPU Accelerated Windows: 0/1 Basic Blocked for your graphics card because of unresolved driver issues. Vendor ID: Tungsten Graphics, Inc WebGL Renderer: Blocked for your graphics card because of unresolved driver issues. windowLayerManagerRemote: false AzureCanvasBackend: cairo AzureContentBackend: cairo AzureFallbackCanvasBackend: none AzureSkiaAccelerated: 0
So, I found Blocklisting/Blocked Graphics Drivers - MozillaWiki, which notes:
Mesa drivers are whitelisted if the Mesa version is at least 7.10.3 (see bug 659560).
Exception: with the Nouveau 3D driver, the Mesa version is required to be at least 8.0 (see bug 729817)
libOSMesa.so.6 doesn't actually check out with
1.4 Mesa 7.10.2, but I thought I'd rebuild from source anyways.
So I got the source of 7.10.3 (
libdrm-2.4.24, unpacked, ran
PKG_CONFIG_PATH=/path/to/Mesa-7.10.3/libdrm-2.4.24 ./configure --enable-gl-osmesa and
make, and indeed, I do get shared library files built libOSMesa.so -> libOSMesa.so.7 -> libOSMesa.so.7.10.3; and if we doubt the version info in the filename, we could also try this:
$ strings -a lib/libOSMesa.so.7 | grep 'Mesa 7' %u.%u Mesa 7.10.3 OpenGL ES-CM 1.%d Mesa 7.10.3 OpenGL ES 2.0 Mesa 7.10.3
Nice, so now I thought, I'll just replace this library as
... and run Firefox with:
LD_LIBRARY_PATH=/path/Mesa-7.10.3/lib LD_PRELOAD=/path/Mesa-7.10.3/lib/libOSMesa.so.7 strace /path/to/firefox -P default -safe-mode -new-instance 2>&1 | grep --color=always 'Mesa.*\.so'
strace even tells me the library has been opened:
open("/path/Mesa-7.10.3/lib/libOSMesa.so.7", O_RDONLY) = 4
... and still - I get this in
about:support, the same as above:
So, it's still referring to Mesa 7.10.2, regardless - and I have no idea why?
Btw, I just now realized that the config setting
webgl.osmesalib may be something hanging in my profile from earlier versions, because if I start
firefox with default profile and safe mode, all I get is
So - how can I persuade firefox, to try the newly built Mesa libraries, instead of the old ones?