[Development] Configure command lines of official Qt releases

[Richard Weickelt]

> Excellent yes. That was a recent addition to the installer framework,
> very useful for exactly that purpose.

Thanks for _all_ replies! Actually, the configure command line in the COIN
logs differs from
https://code.qt.io/cgit/qtsdk/qtsdk.git/tree/packaging-tools/bld_config?h=v5.12.3-packaging
so I rather used the ones from the COIN logs.

Could somebody explain why the Linux release explicitly specifies "-R ." as
configure option? I have never seen that being used before.

Richard