Mercurial: abort: no username supplied (see “hg help config”)

While submitting bug fix to Symbian ORG, I got

M:\sf\adapt\qemu>hg commit -m "Bug xxx - My proposed fix for xxx"

abort: no username supplied (see "hg help config")

I solved the problem by creating a file: Mercurial.ini under

c:\Program Files\TortoiseHg\

with the content

[ui]
username = Firstname Surname
verbose = True