I'm noticing this when we're doing "arc patch" on the build server (this is on Windows):
```
167 Created and checked out branch arcpatch-D1861.
168 Checking patch AAAAAA.cs...
169 Checking patch BBBBBB.cs...
170 Applied patch AAAAAA.cs cleanly.
171 Applied patch BBBBBB.cs cleanly.
172
173 Cherry Pick Failed!
174 Exception
175 Command failed with error #1!
176 COMMAND
177 git cherry-pick "arcpatch-D1861"
178
179 STDOUT
180 # On branch master
181 # You are currently cherry-picking.
182 # (all conflicts fixed: run "git cherry-pick --continue")
183 # (use "git cherry-pick --abort" to cancel the cherry-pick operation)
184 #
185 nothing to commit, working directory clean
186
187
188 STDERR
189 The previous cherry-pick is now empty, possibly due to conflict resolution.
190 If you wish to commit it anyway, use:
191
192 git commit --allow-empty
193
194 Otherwise, please use 'git reset'
195
196 (Run with --trace for a full exception trace.)
```
There doesn't appear to be any errors from the cherry pick operation, but Arcanist says it failed because the cherry pick is empty. The change is definitely not yet in the repository when this build ran (and still isn't).