There is a report in Debian BTS about problems with extended characters.
A reported workaround is typing in a text editor and pasting to
qcad. But two letters persist not working: "ã" and "õ".
It was reported for 18.104.22.168-1.
Details on Bug#507368.
Please improve the extended characters support.
Patches from community are welcome
Can't type text with çãõâôáéíóúàü