Nightly on a Motorola Moto G5:
Startup crash when enabling gfx.webrender.software.

Crash report: bp-69657656-b9f1-4a20-b42a-0ccef0201012

Reason: SIGSEGV /SEGV_MAPERR

Top 10 frames of crashing thread:

0 libxul.so RustMozCrash mozglue/static/rust/wrappers.cpp:17
1 libxul.so mozglue_static::panic_hook mozglue/static/rust/lib.rs:89
2 libxul.so core::ops::function::Fn::call src/libcore/ops/function.rs:72
3 libxul.so std::panicking::rust_panic_with_hook src/libstd/panicking.rs:474
4 libxul.so rust_begin_unwind src/libstd/panicking.rs:378
5 libxul.so std::panicking::begin_panic_fmt src/libstd/panicking.rs:332
6 libxul.so core::panicking::panic src/libcore/panicking.rs:52
7 libxul.so webrender_bindings::swgl_bindings::SwCompositor::queue_composite gfx/webrender_bindings/src/swgl_bindings.rs:950
8 libxul.so webrender_bindings::swgl_bindings::SwCompositor::flush_composites gfx/webrender_bindings/src/swgl_bindings.rs:1028
9 libxul.so <webrender_bindings::swgl_bindings::SwCompositor as webrender::composite::Compositor>::unbind gfx/webrender_bindings/src/swgl_bindings.rs:1318

I'm struggling to see how we crash here exactly, looking at the crash report it seems that some of the stacks might be confused.

We don't currently have support for software drawing on Android, the widget layer doesn't expose pixel access since we've always used OpenGL in the past.

I can reproduce this signature by using picture-in-picture with sw-wr (on linux).