I just updated qgis-server package to latest 3.2.x from Ubuntugis repository (ubuntugis-unstable) and everything works fine - but font rendering. All labels on tiles, legend and print templates show up as squares:
After upgrading I got a lot of this messages in nginx error log:
QFontDatabase: Cannot find font directory /usr/lib/x86_64-linux-gnu/fonts - is Qt installed correctly?
I could fix that by adding a symbolic link from /usr/lib/x86_64-linux-gnu/fonts to /usr/share/fonts and updating font cache with
fc-cache -fv. But this brought no changes to visualization of labels.
The QGIS project uses Ubuntu font installed from ttf-ubuntu-font-family package and shows up fine on QGIS Desktop. The font is also listed on the server using
There are no error messages related to fonts neither in nginx error log nor in QGIS Server logging. Could be related to Qt so, any hints?