It's been reported here, too: https://discourse.slicer.org/t/qt5-build-a-few-hiccups/952/4

I won't have time to work on this before the new stable version is released (in a couple of weeks), but it would be great if someone else could have a look before then.

Ok, perfect. I didn't see the post in discourse. I have also a couple of busy weeks, not sure that I have the time to check it before you.

I'll take a look once I'm back in Canada

perfect, thanks Csaba.

It took me a while to build Slicer with Qt5 and VTK8 on Windows, and the crash does not occur like this:

1. Load MRHead
2. Open Segment Editor
3. Add segment
4. Click Paint

I played around and Segment Editor seems to work fine.

Did you reproduce it differently? If the latest trunk yields a crash for you doing these steps on Linux, then I'll need to build it on Linux too.

Hi Csaba, thanks for testing on windows. It seems a bug on linux/Qt5 build. I made a pull request with a simple fix:
https://github.com/Slicer/Slicer/pull/811

May you check it and in case merge it?

For reference, the bug was report for ArchLinux as well:
https://discourse.slicer.org/t/qt5-build-a-few-hiccups/952

Excellent, thanks for the fix, Davide! It makes complete sense and it's otherwise harmless so I'll simply integrate it.

Integrated Davide's fix in https://github.com/Slicer/Slicer/commit/7de0d6a6e71694ac808a2e73da3fd3c3300f708c

Closing the issue, as the fix comes from the reporter.