After upgrading to git 2.19 the messages are in Spanish.
I don't have LANG set, but after setting it to English:
export LANG="en_US.UTF-8"
Then it works again, but before upgrade, it wasn't necessary to set up explicitly the language (what did it change the default recognition?)
UDPATE1:
https://github.com/Homebrew/homebrew-core/pull/32008
https://public-inbox.org/git/CAKd-JgS3omKbN+OzQL2dUun6Seg9CjDNk8KEj9m83xdTZE=7FA@mail.gmail.com/T/
This issue has been seen in other command-line as wget.
All point to be gettext() ?
UPDATE2:
https://github.com/Homebrew/homebrew-core/issues/31980 still researching gettext.