There are a dozen tickets to rename test packages to conform with the standard patter, e.g. ShoutTests --> Shout-Tests. The META case is... https://pharo.fogbugz.com/default.asp?14447 The <Merge> of these slices seems to be failing, for example, due to the non-existant Shout-Tests being created while reviewing the merge, prior to the second <Merge> button being pressed to approve the merge. A side-effect is that the if you cancel the merge, the new empty Shout-Tests remains in the image, which I think itself is a bug, but might be unrelated to merge conflict. To observe this... 1. Open System Browser and filter on 'shout' 2. Open Monticello and the Pharo4Inbox. 3. Select SLICE-Issue-14439... and <Merge> 4. Observe that packages Shout-Tests and SLICE-Issue-14439... have been created already, prior to actually committing the <Merge> 5. Observe that there is 1 merge conflict. 6. <Cancel> the Merge 7. Observe that packages Shout-Tests and SLICE-Issue-14439... remain Now this problem only occurs when loading the SLICE-Issue-14439...mmz, not when loading the related Shout-Tests...mcz. To observe... 1. Remove empty packages Shout-Tests and SLICE-Issue-14439... 2. In Monticello, select Shout-Tests..1.mcz and <Merge> 3. Observe no merge conflicts. =================== I managed to reproduce as follows... 1. Create a package "Case14616" 2. Add a tag "MyTag" 3. Add a class "MyClass" into "MyTag" 4. Create "SLICE-Issue-14616...", adding dirty "Case14616" 5. Save the slice to your local package-cache 6. Open a virgin Image 7. Merge "SLICE-Issue-14616...". --> Observe the merge ccnflict. I have logged https://pharo.fogbugz.com/default.asp?14616 but I am not familiar with the Monticello architecture. Could someone who is take a look? cheers -ben