fatal: bad revision 'git rm -r --ignore-unmatch -- folder'

Hi there,

I'm trying to purge a complete folder and its files from the
repository history with:

git-Games# git filter-branch 'git rm -r --ignore-unmatch --
Ubuntu/16.04/' --tag-name-filter cat -- --all HEAD
fatal: bad revision 'git rm -r --ignore-unmatch -- Ubuntu/16.04/'

git does not find the folder although it's there:

git-Games# ll Ubuntu/16.04/
total 150316
drwxr-x--- 2 actionmystique actionmystique     4096 Nov 19 13:40 ./
drwxr-x--- 4 actionmystique actionmystique     4096 Oct 30 14:02 ../
-rwxr-x--- 1 actionmystique actionmystique  2190394 May  9  2016
residualvm_0.3.0~git-1_amd64.deb*
...
-rw-r--r-- 1 actionmystique actionmystique 67382492 Oct 13 09:15
scummvm-dbgsym_1.9.0_amd64.deb

What is going on?

-- 
Jean-Christophe