Fwd: Unknown option for merge-recursive: -X'diff-algorithm=patience'

Hello,

I am running git 2.15.1 and facing the following issue with linux kernel tree.

# git checkout v3.8 # git branch abc-3.8 # git checkout v3.9 # git branch abc-3.9 # git checkout abc-3.8

Introduce new commit on top of abc-3.8. Here, I edit README.

# vim README # git commit -a -v [abc-3.8 4bf088b5d341] Hello world

Then I try to rebase abc-3.9 on top of abc-3.8 as the following:

# git rebase --preserve-merges -s recursive -Xdiff-algorithm=patience --onto abc-3.8 v3.8 abc-3.9

And then I see:

fatal: Unknown option for merge-recursive: -X'diff-algorithm=patience' Error redoing merge e84cf5d0fd53badf3a93c790e280cc92a69ed999

Attached here is GIT_TRACE=1 output.