Unable to build AUR package efax-gtk 3.2.13-4 on manjaro xfce kernel 5.10.26-1
Can compile source found at Upstream URL
The source code for the most recent stable version is efax-gtk-3.2.15
Extract contents of the downloaded efax-gtk-3.2.15.src.tgz file.
Follow instructions in file INSTALL found in the soruce folder that was extracted from the archive file.