Crash report: https://crash-stats.mozilla.org/report/index/293f220a-f8d6-47c2-86f6-5064e0210126

MOZ_CRASH Reason: MOZ_CRASH()

Top 10 frames of crashing thread:

0 firefox-bin mozalloc_abort memory/mozalloc/mozalloc_abort.cpp:33
1 libxul.so std::string::string /builds/worker/fetches/clang/include/c++/7.4.0/bits/basic_string.tcc:664
2 libxul.so mozilla::gl::GLContext::InitImpl gfx/gl/GLContext.cpp:541
3 libxul.so mozilla::gl::GLContext::Init gfx/gl/GLContext.cpp:321
4 libxul.so mozilla::gl::GLContextEGL::Init gfx/gl/GLContextProviderEGL.cpp:435
5 libxul.so mozilla::gl::GLContextEGL::CreateGLContext gfx/gl/GLContextProviderEGL.cpp:784
6 libxul.so mozilla::gl::GLContextEGL::CreateEGLPBufferOffscreenContextImpl gfx/gl/GLContextProviderEGL.cpp:1192
7 libxul.so mozilla::gl::GLContextEGL::CreateEGLPBufferOffscreenContext gfx/gl/GLContextProviderEGL.cpp:1213
8 libxul.so mozilla::gl::GLContextProviderEGL::CreateHeadless gfx/gl/GLContextProviderEGL.cpp:1227
9 libxul.so mozilla::WebGLContext::CreateAndInitGL dom/canvas/WebGLContext.cpp:367

Fixed by backout of bug 1688668.

It appears fGetString(LOCAL_GL_VERSION) can return a nullptr on Linux.
This causes a crash when we try to assign it to an std::string. This
appears to happen predominantly llvmpipe users (although generally that
should return a GL verison string as well). This patch ensures we
gracefully fail to init GL instead.

https://hg.mozilla.org/mozilla-central/rev/ed2285c6cf09

The patch landed in nightly and beta is affected.
:aosmond, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment on attachment 9259798 [details]
Bug 1688999 - Fix crash with null GL_VERSION string on Linux.

Beta/Release Uplift Approval Request

• User impact if declined: Low volume of crashes on Linux.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This patch just adds a check for a null pointer and disables GL if so, trivial patch. It is often a startup crash in the parent process so it can't get much worse.
• String changes made/needed:

Comment on attachment 9259798 [details]
Bug 1688999 - Fix crash with null GL_VERSION string on Linux.

Approved for 97.0b8.

https://hg.mozilla.org/releases/mozilla-beta/rev/568460ad023f