What version are you running? site 2.0.15 rbt 0.7.4 What's the URL of the page containing the problem? http://reviews.internal/r/67/ What steps will reproduce the problem? 1. given a mercurial repository where tip is hash AAAAA 2. make two commits locally with hash BBBBB, and CCCCC 3. rbt post --parent AAAAA 4. open in web ui and look at diff What is the expected output? What do you see instead? The diff from AAAAA to CCCCC. What I see is "Didn't apply patch cleanly". Downloading the patch and applying it locally is fine: cd mercurial-repository wget -Opatch http://reviews.internal/r/67/diff/raw hg update -r AAAAA patch -p1 < patch Looking at the contents of the patch we see: diff -r AAAAA -r CCCCC filename ... The problem is "-r CCCCC", if we remove it and re-upload the patch it diffs fine. This is a but in rbt where it is adding the "-r CCCCC" Workaround: rbt diff --parent AAAAA | perl -pe 's/^(diff -r \w+) -r \w+/\1/g'> patch upload patch This means I cannot use rbt post What operating system are you using? What browser? Mac OS X Safari Please provide any additional information below.