We’re seeing dotnet crash sporadically with a sigsev or sigbus when running on mac os. This is in the dotnet executable itself, and can happen on commands like `dotnet build`, not just on executing the built assembly. in fact, this seems to be where we most often see it.
This is happening very infrequently. For one of our projects we see this once or twice a week across thousands of dotnet invocations.
Based on an analysis of the dotnet diagnostics (attached) it appears to be a manifestation of this issue in dotnet https://github.com/dotnet/runtime/issues/119761\#issuecomment\-4780332027
This issue is fixed in this change Use volatile access for CoreCLR dictionary layout publication by Copilot · Pull Request #129763 · dotnet/runtime · GitHub, but that fix landed after the current version of dotnet in Unreal
So my actual question is, could we request that the copy of the dotnet sdk in Unreal be bumped up to the latest patch version. We can then cherry pick that into our various projects. No preference on our side between UE5-main or UE6-main, we consume changes from both atm.
If you prefer, I could make the change and put it up as a PR. But given that it’s just a huge pile of downloaded files, that seemed more cumbersome for you to take than to just run the script yourselves. lmk if there is anything we could do to help, though.
dotnet-2026-09-21-212417.ips.txt(109 KB)