I let “Git Gui” AKA git-gui (on cygwin) “Compress Database”, and the database was corrupt then

• https://git-scm.com/docs/git-gui

The differences between the master and the local copy were not big enough, so I resorted to re-cloning:

• https://stackoverflow.com/questions/8271263/repair-corrupted-git-repository – I actually followed Niel de Wet’s advice (https://stackoverflow.com/users/297331/niel-de-wet) and “I simply replaced the .git folder in the broken repo with the one I recloned“