In an attempt to codesign gdb, I used an incorrect certificate, so now gdb is codesigned but does not work as expected.
I attempted to codesign gdb using the correct certificate, however codesign complains that gdb is already signed.
So how to undo it?
The codesign command I used was:
codesign -s gdb-cert gdb
It's not well documented at all, from what I can tell, but you may be able to remove code signing via:
codesign --remove-signature gdb