I'm a relative beginner with Git, git-xl 0.4, and SourceTree, and I've been playing around with using these tools to manage some xlsm files. Sorry for the double post (https://community.atlassian.com/t5/Sourcetree-questions/SourceTree-VBA-Macros-via-xltrail/qaq-p/818400), but I figured posting a new question instead of an answer may get me some traction.
Everything seemed to be working swimmingly, but I ran into some trouble when I edited a VBA module in one of my xlsm files and then observed it in Sourcetree.
When I try to stage or discard lines/hunk, I get the following error:

The content of that file is:
diff --git a/diff_results.xlsm b/diff_results.xlsm
--- a/diff_results.xlsm
+++ b/diff_results.xlsm
' Return code?
Call RunPowerShell(cmd, "CompareResults")
[31m-' dummy comment added
[32m+' dummy comment revised after being added
End Sub
Sub CallCompareResults()
I verified that I could discard hunk with a change to a simple text file, so I think my basic sourcetree and repo setup is right. Perhaps git-xl doesn't support patching like this? Or might something else be the problem?