Problem with fonts loading for RapidPhotoDownloader AppImage

[aferrero2707]

I am trying to provide an AppImage package for the Rapid Photo Downloader program, which is a PyQt5-based application that allows to copy and organize pictures from digital cameras.

The current AppImage build scripts can be found on GitHub here (the relevant scripts are bootstrap2.sh and mkappimage). They already allow to generate a working AppImage package, but I have an issue with fonts that is really driving me crazy... When running as an AppImage, the program uses an ugly monospace font instead of the one inherited from the desktop UI theme.

This is how the application should look like under Mint 17.2 with the default Mint-X theme:

and this is how the program looks like when executing the AppImage:

I have used strace to check which font files are actually accessed by the application , and here is the result (left is the normal application, right is the AppImage):

As one can see, the AppImage falls back to the MonoSpace font instead of loading the DejaVuSans.ttf one. Note that other fonts are loaded correctly...

Does anybody have an hint of what could be the cause of this, or has anybody already run into a similar issue?

Thanks in advance!

[probonopd]

I'm clueless... trial end error is your friend here. I would start by sequentially deleting all font-related libraries from the AppImage, and retrying.