Pb building a qt5 app

Hi everyone !
I have some trouble in making a snap from my qt5 app. This project needs at least QT5.10, and poppler libs. I’m currently using the x-qtbuilder plugin to get a more recent version of QT.
Anyway, i can’t get the snap building, and it’s complaining about not finding the qt sub-module …
here is the yaml file and the snapcraft log.
Any help would be greatly appreciated

possibly-not seeing the log-archive for most users.

here is the log :

ERROR: No value supplied to command line option ‘prefix’.
./configure --prefix= -prefix /opt/Qt -bindir $SNAP/usr/bin -release -confirm-license -opensource -plugin-sql-mysql -plugin-sql-tds -platform linux-g+±64 -system-harfbuzz -system-zlib -system-libpng -system-libjpeg -openssl -no-rpath -verbose -optimized-qmake -dbus-linked

Exited with code 3.
Verify that the part is using the correct parameters and try again.
Build failed