arbitrary .asc files appearing since I use gpg-from-sq

in https://bugs.debian.org/1087125 Martin Dosch martin@mdosch.de reported:

Package: gpg-from-sq
Version: 0.11.2-4
Severity: normal

Dear Maintainer,

since I am using gpg-from-sq I often find weird .asc files cluttered around my file system. I have no idea why and when they appear. I was deleting all of them a few days ago and when a checked again today, there were new weird .asc files:

find ~ -name \*\&\*.asc
/home/martin/build/ronn-ng/-&9.asc
/home/martin/build/gummi/-&11.asc
/home/martin/build/go-sendxmpp/-&9.asc
/home/martin/-&11.asc
/home/martin/-&15.asc
/home/martin/-&14.asc
/home/martin/-&9.asc
/home/martin/-&119.asc