It looks like `libstdc++` and `libc++` only define this `enum class` member
when the `ETIME` macro is defined. To prevent build errors when this macro
is not defined it makes sense to check for this error only conditionally.
Not sure why `QString::toStdWString()` doesn't work with this compiler and
the official Qt 6.5.0 build. However, instantiating an `std::wstring`
manually works so let's just use this as a workaround.
Note that with GCC/mingw-w64 and Qt 6.4.3 the `QString::toStdWString()`
function works just fine.