Seems a lot of us have been experiencing crashes in the current Icecat. in Guix master. Ricardo Wurmus gave me a nice tip that seems to have fixed the problem here:
<rekado> go to about:config <rekado> find the keys gfx.canvas.azure.backends and gfx.content.azure.backends <rekado> for both change “cairo” to “skia” <rekado> note that for me this results in less readable fonts Seems to work here! (I haven't noticed the font issue but I could just be missing it.)