Unsolved Autocompletion Does Not Work Reliably With g++ 9 and 10

[JoeC_58]

Re: Qt Creator completion stopped working

My setup:
Ubuntu 20.04, CMake 3.16.3, Qt Creator 4.11.0, Qt 5.12.8. I have gcc 8, 9 and 10 installed.

I started with g++ 9 configured as my default compiler and noticed autocompletion worked for some class objects but not others. The simplest object which did not autocomplete was a string. My test code included:

std::string str;
str.   // <-  autocompletion popup expected after typing the period

With kit configured to use compiler g++ 9 or 10, there was no popup. But with the g++ 8 compiler, I did get the popup

[JonB]

@JoeC_58
Do you use the (default?) clang module for your code completion?

[JoeC_58]

@JonB If you mean ClangCodeModel plugin, no. I deselected that.