Qt Creator crashes reproducibly for me when typing the following into the editor (editing a .cpp file):

void foo() { if (alignof

It crashes reliably at the last letter of the above line. The last message on the command line indicated the clang backend crashes and tears down creator as well:

ConnectionServer error: "QLocalSocket: Remote closed" "/tmp/QtCreator-kdXgtA/ClangBackEnd-13572"
Segmentation fault (core dumped) ~/Qt/Tools/Preview/Qt\ Creator\ 4.11.0-beta2/bin/qtcreator

So this sounds like two problems, the crash in the clangbackend and that creator can't handle it.

I'm running Ubuntu 18.04 btw.