I just installed Manjaro Linux and I could not find a pre-compiled version for Manjaro. I am a real noob here...
I tried the amazingly simple command
pamac build wsjtx and it produced what appeared to be an identical result. Then Karza suggested renaming the offending file for Japanese translations and it worked!
Here is what I did:
sudo mv /usr/share/qt/translations/qtbase_it.qm /usr/share/qt/translations/qtbase_it.qm.bak
sudo mv /usr/share/qt/translations/qtbase_ja.qm /usr/share/qt/translations/qtbase_ja.qm.bak
sudo mv /usr/share/qt/translations/qt_it.qm /usr/share/qt/translations/qt_it.qm.bak
sudo mv /usr/share/qt/translations/qt_ja.qm /usr/share/qt/translations/qt_ja.qm.bak
then I simply typed in
pamac build wsjtx
and let 'er rip!