Crash report: https://crash-stats.mozilla.org/report/index/39636e9a-c109-4024-a0f5-e23680201007

Reason: EXCEPTION_BREAKPOINT
MOZ_CRASH Reason: already borrowed: BorrowMutError

Top 10 frames of crashing thread:

0 xul.dll RustMozCrash mozglue/static/rust/wrappers.cpp:16
1 xul.dll mozglue_static::panic_hook mozglue/static/rust/lib.rs:89
2 xul.dll core::ops::function::Fn::call<fn ../4fb7144ed159f94491249e86d5bbd033b5d60550/src/libcore/ops/function.rs:232
3 xul.dll std::panicking::rust_panic_with_hook ../4fb7144ed159f94491249e86d5bbd033b5d60550//src/libstd/panicking.rs:474
4 xul.dll std::panicking::begin_panic_handler ../4fb7144ed159f94491249e86d5bbd033b5d60550//src/libstd/panicking.rs:378
5 xul.dll core::panicking::panic_fmt ../4fb7144ed159f94491249e86d5bbd033b5d60550//src/libstd/panicking.rs:332
6 xul.dll core::option::expect_none_failed ../4fb7144ed159f94491249e86d5bbd033b5d60550//src/libcore/option.rs:1211
7 xul.dll webrender_bindings::swgl_bindings::{{impl}}::add_surface gfx/webrender_bindings/src/swgl_bindings.rs:1401
8 xul.dll webrender::renderer::Renderer::render_impl gfx/wr/webrender/src/renderer.rs:3947
9 xul.dll webrender_bindings::bindings::wr_renderer_render gfx/webrender_bindings/src/bindings.rs:614

A few reports up to now starting with Nightly build id 20201006041051

Maybe a regression from Bug 1651882? (Or rather a bug that was previously masked by the issue causing Bug 1651882?)

(Simon Giesecke [:sg] [he/him] from comment #0)

Crash report: https://crash-stats.mozilla.org/report/index/39636e9a-c109-4024-a0f5-e23680201007

GraphicsCriticalError |[G0][GFX1-]: Failed to link shader program: debug_font
(t=4.06593) |[G1][GFX1-]: Failed to link shader program: debug_font
(t=5.93593)

I don't think this will be related to https://bugzilla.mozilla.org/show_bug.cgi?id=1651882 - was that based only on the text of the panic, or was there some other correlation between them?

This looks more like an unrelated SWGL related bug, I think.

(In reply to Glenn Watson [:gw] from comment #3)

I don't think this will be related to https://bugzilla.mozilla.org/show_bug.cgi?id=1651882 - was that based only on the text of the panic, or was there some other correlation between them?

Sorry I should better have made that explicit: My assumption was based on the last change to gfx/wr/webrender/src/renderer.rs coinciding with the first appearance of the signature. But it seems Lee has made the right match now :)