after configuring merge.conflictstyle automatically with -s, git-mediate causes parse error

[eshels]

{eshels-MBP:ui2} % git-mediate -d                                                                                                                                                                                                                                                                                                                 (15:13:39:eshel:HEAD !)
git-mediate: user error (merge.conflictstyle must be diff3 but is "unset". Use -s to automatically set it globally)
{eshels-MBP:ui2} % git-mediate -s -d                                                                                                                                                                                                                                                                                                              (15:13:42:eshel:HEAD !)
git-mediate: Parse error: failed reading up to marker: '|', got:
12	    initialize: (attributes, options) ->
13	=======
14	    initialize: (attributes, options) =>
15	>>>>>>> fe/handle constructors
16	        @stat_meta = options.stat_meta
CallStack (from HasCallStack):
  error, called at src/Conflict.hs:66:13 in main:Conflict

recreating the conflict fixes issue, but maybe it could get fixed automatically?