arc land failing

I haven't been able to arc land in GHC for a while, it always complains about not being able to fast-forward, like this: $ git pull --rebase First, rewinding head to replay your work on top of it... Applying: Mask to avoid uncaught ^C exceptions $ arc land Landing current branch 'ghci-mask'. Switched to branch master. Updating branch... Switched back to branch ghci-mask. Exception Command failed with error #128! COMMAND git pull --ff-only --no-stat STDOUT (empty) STDERR fatal: Not possible to fast-forward, aborting. (Run with --trace for a full exception trace.) [1] 11904 exit 1 arc land Anyone able to look into this? Cheers, Simon