evolve: dedupe divergents when running evolve --all --any or evolve --rev Before this patch, when running evolve --all --any or evolve --rev with the --divergent flag, we were selecting all of the divergents. After solving the first one, its counterparts would get pruned and potentially hidden which would crash when trying to resolve them. This patch introduces logic to dedupe the divergents to be resolved by keeping only one per group of divergent with the lower revision number.

evolve: remove unused warning message in _solvedivergent Before this patch, we were checking for a case where a divergent changeset could be public and printing a warning in that case. When we compute the divergent set in the obsolete module we explicitely look for not public() changesets. This patch removes this unused warning.

compat: use svfs instead of sopener The "new" attribute is about 2 years old so let's move on.