`mutt -v` gives wrong version and date

I just built mutt anew from eca744f5, i.e., HEAD of master (not stable). After doing this, mutt -v should show 1.9.3, possibly with a plus-something for the bookkeeping commits. However, I get:

Mutt 1.9.2+91 (eca744f5) (2018-01-21)

The version is wrong and so is the date. Only the commit number is right.