Author: (no author) not defined in authors file

I came across the following error message:

Author: (no author) not defined in authors file

when I tried to import an SVN repository (Open Yahtzee‘s) to Git using git svn, and I specified an authors file (using -A). Indeed, the first commit to SVN (which was done using cvs2svn) had no username for the committer. Apparently, the workaround is to add the following line to your author file.

(no author) = no_author <no_author@no_author>

I also tried doing the same without an email address, but it just didn’t work. It seems Git requires that all authors have an email address.