The commit mentioned in the title assumes that a QStringRef instance can be cast to a const Qstring automatically. I don't know what Qt version introduced that compatibility but it's not in Qt 5.9 . Adding an explicit .toString() fixes the build failure.
please fix it then
I don't think we have to be concerned with the potential additional overhead of creating a copy of the string as `toString()` appears to do? I don't see anything about a new cast operator in the Qt 5.15 documentation for QStringRef nor any new overloads of QVersionNumber::fromString() that would be used here so it's a bit of a mystery to me why the code builds as is.
> it's a bit of a mystery to me why the code builds as is. Got that: newer versions of QVersionNumber::fromString() can take a QStringView, which has a ctor taking a QStringRef.
so, can you then please fix it? you didn't even paste an error message that would show which file fails to build with that old Qt version
Apologies, my bad. The failure is in DebugSession::handleVersion() in plugins/gdb/debugsession.cpp (line 288 to be precise).
Git commit 87979acc1a6c9f401d3c19ab516fa38b1d053233 by René Bertin. Committed on 30/11/2020 at 18:54. Pushed by rjvbb into branch '5.6'. Restore compatibility with Qt < 5.10 M +1 -1 plugins/gdb/debugsession.cpp https://invent.kde.org/kdevelop/kdevelop/commit/87979acc1a6c9f401d3c19ab516fa38b1d053233