Easy to reproduce: `JPEGReadWriter2Test suite run` with a VM compiled with cygwin (mingw cross platform) toolchain. This might be related to this commit or not: https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/7e0018d2bda239f11f6...
The commit tells that assert VM crashes even when built with MSVC toolchain (w or w/o clang-cl.exe).