[netsurf-dev] Help identifying cause of assert

Hi all

In the AmigaOS3 frontend I'm getting the following when visiting https://github.com/jens-maus/amissl (and other GitHub pages):

(0.000034) [ERR  flex] content/handlers/html/layout_flex.c:246 layout_flex_item: box 0x42bd06ac: layout failed
(0.230806) [ERR  flex] content/handlers/html/layout_flex.c:246 layout_flex_item: box 0x42bcdb94: layout failed
(0.341922) [ERR  flex] content/handlers/html/layout_flex.c:246 layout_flex_item: box 0x42bc4da4: layout failed

followed by the assert:

"containing_block->width != UNKNOWN_WIDTH" failed in file "content/handlers/html/layout.c", line 4481

As this works on the AmigaOS4 frontend and there is minimal difference in the layout/window related code, I'm at a loss as to what is causing it.  Can anybody provide any pointers?

Chris