Move command fails with git filter-branch -

i'm trying use git filter-branch rename directory in repository.

the command try use, without success far, is:

git filter-branch --tree-filter "mv engine src" --force head

but yields following result:

rewrite dddd2d70eee09d5600f7aeb87ca8321be5ed6aee (1/888)mv: rename engine src: no such file or directory

tree filter failed: mv engine src

i don't understand why, simple move command works on own... what's directory/file not found, , how can fix that?

i'm on macosx 10.10.5 , use zsh if helps.

disclaimer: don't care here discussion doing git mv or mv instead of that, i've read , not point here. want know why fails way does.