Copying a qt5 build to a different host machine

vikramg

I have successfully cross-built qt5 for the Odroid C2 in a qt5-build directory on an Ubuntu x86-64 host machine. (Configured thus:

-sysroot ~/Projects/Odroid/C2/sysroot 
-prefix /usr/local/qt5c2 
-hostprefix ~/Projects/Odroid/C2/Qt/qt5-build

)
This works fine, and I am able to build and deploy an application on the target device via Qt Creator. I want to enable another host machine (also Ubuntu x86-64) to facilitate development, and thought the process would be as simple as copying my qt5-build directory to the second host.

To my surprise, this does not work at all, owing to hardcoded paths in various places. Per this SO post I tried creating a qt.conf with

[Paths]
Prefix = ./../

With this, "qmake -query" does return the correct paths. However, QtCreator still barfs when I try to select this qmake as my desired Qt version.

Then I tried "qmake -set" as suggested in another post in the same SO thread:

$ ./qmake -set QT_HOST_PREFIX /opt/Qt/Odroid-C2/qt5-build
$ ./qmake -set QT_SYSROOT ~/Projects/Odroid/C2/sysroot

(The paths here are correct for the new host machine I wish to enable).
However, it still does not work in QtCreator.

So: how does one copy/move a Qt build from one host machine to another? Surely it should not require rebuilding Qt from source on every host I'd like to enable. One workaround I can think of is to build on the original host with generic paths under /opt wherever path specification is required, and replicate that structure on all other hosts. But it just feels like there ought to be a real solution to this rather than workarounds.

sierdzio

The official recommendation is not to copy the libs after building. The way Qt installers go around it is indeed by using qt.conf.

I guess the easiest way is indeed to preserve the same paths in all machines. Not very convenient, but will work.

vikramg

I have verified that preserving the same paths (in my case, /opt/Qt) on all hosts for the cross-compiled output, works fine.