Build pulled from: https://github.com/avrdudes/avrdude
Snapshot from 3/13/22 (da1271642e4e211a9b8be69d43dc725f105fe0dc).
Built in Cygwin 3.3.4 (x64), because... I'm not a smart person. All options are enabled.
Repo includes all Cygwin dependencies for a standalone, relocatable install (I think?!).