hg evolve fails with "no support for evolution merge changes yet" error on a linear repository

[Pierre-Yves David]

On 03/25/2014 03:08 AM, Angel Ezquerra wrote:
> On Tue, Mar 25, 2014 at 10:45 AM, Pierre-Yves David
> <pierre-yves.david at ens-lyon.org> wrote:
>>
>>
>> On 03/25/2014 02:22 AM, Angel Ezquerra wrote:
>>>
>>> Hi,
>>>
>>> I wanted to post this to the new evolve-testers mailing list, but I'm
>>> still waiting for my subscription to be approved. I hope it is OK to
>>> post this here.
>>>
>>> I'm using the latest stable revision of the mutable-history repository
>>> (revision 6a67606e1c34).
>>>
>>> I often get the "no support for evolution merge changes yet" error
>>> when I try to use any advanced feature of the evolution extension. In
>>> particular when I use evolve.
>>>
>>> For example I just used fold on a completely linear repository. The
>>> repository contains a single file. It had 11 revisions on a single
>>> topological branch. The repository had a few hidden revisions which
>>> were the result of using amend a few times. I wanted to fold the first
>>> 7 non hidden revisions In this repository, I did:
>>
>> Is this:
>> https://bitbucket.org/marmoute/mutable-history/issue/35/abort-no-support-for-evolution-merge
>> ?
>
> Yes. The main difference is that the repository in which this happened
> ins much simpler and completely linear


So, new data, more chance to build a repro. Cool, can you update the 
bug? (in a concise manner if possible) ?

> (also I believe that at the
> time you suggested that we should discuss these things in the
> mercurial-devel mailing list?).

Yes public discussion is better.

> As I said on my previous email, it worries me a bit that we are
> suggesting people to use evolve now when it is still quite easy to
> encounter these sorts of problems.


This bug is very rare. You happen to meet it more than every body else.

Until we provide a proper fix for it, we could consider a simple patches 
that prevent evolve to try to evolve a changeset above itself. This 
would limit the consequence of the issue.

(and note that I'm suggesting people to use evolve with big flashy 
warning all along the way)

> MQ is complex, and has many limitations, but it is quite reliable in my experience.

On my experience I had less troubles with people using evolve than with 
people using MQ.

(conclusion, (1) please update the bug (2) consider sending the 3 line 
patches that prevent evolve to have source == destination)

-- 
Pierre-Yves David