The docker-bake.hcl file allows target names to contain "/" (in my case the target name was the same as the tag I planned to use).
However, this breaks the --push option because it is a shorthand for --set=*.output=type=registry, and * does not match slashes wich results on this error, which took me time to understand since I did not use the * syntax myself :

error: could not find any target matching '*'

A simple workaround for me was to prevent using slashes in my target name.

However I think it would be more consistent to prevent using slashes in the target name right from the beginning, or to find a way to make it compatible with the push option.