if you want to benefit from an LTS, even with free version of Qt, you have to use the latest minor release available, that is 6.5.6, which brings some bugfixes and security patches.
If you use 6.5.0, you won't benefit those fixes that have been introduced from 6.5.1 to 6.5.6.
And it's the same for any version, not only LTS.
@Christian-Ehrlicher said in Error during build from source (AutoMOC):
There is no advantage for a non-paying customer to stick at a LTS version at all.
I personnaly prefer using the latest LTS over latest version when I don't need the new features as new features also come along with potential new bugs and security issues.
Use the pre-compiled binaries from the Qt online installer - much easier to use and no problems during compilation.
I agree, self-building is not needed.