What exactly does that mean?
I got that while exploring the git annex command:

shiny-2:git-annex ovi$ pwd
/Users/ovi/Sharing/git-annex
shiny-2:git-annex ovi$ git annex map
map /Users/ovi/Sharing/git-annex ok

  running: dot -Tx11 /Users/ovi/Sharing/git-annex/.git/annex/map.dot

failed
git-annex: map: 1 failed
