mutable-history / docs / evolve-faq.rst

Evolve How To

Add a changeset: commit

Just use commit as usual. New changesets will be in the draft phase.

Rewrite a changeset: amend

A dedicated command hg amend is added by the extension. It writes a new changeset combining working-directory parent changes and parent. It will work on any draft or secret changeset. It will not work on public changesets.

To understand what the result of amend will be I use the two following aliases [1]:

# diff what amend will look likes
pdiff=diff --rev .^

# status what amend will look likes
pstatus=status --rev .^

It takes various options to pick an author, a date and the branch of the result... (see hg help amend for details).

This command can even be invoked on changesets with children (provided none is public) !


The amend command is very similar to mq's qrefresh, a refresh alias for amend is also available. But note that contrary to qrefresh, amend does not exclude changes on file not specified on the command line.

XXX add idank example


The hg commit --amend switch does not lay obsolete marker down yet. You should always prefer the dedicated command.

[1](added by

Move a changeset: graft

The graft command introduced in 2.0 allows to "copy changes from other branches onto the current branch".

The graft command has been altered to allow the creation of an obsolete marker between both the result cset and its source (actually recording changeset movements).

This is achieved using a new flag -O (or old-obsolete) [2].

XXX Need a few examples here.


when using graft --continue after conflict resolution you MUST pass -O or -o flag again because they are not saved for now

[2]add this -O to graft instead of a dedicated command is probably abusive. But this was very convenient for experimental purposes. This will likely change in non experimental release.

Delete a changeset: kill

A new ``kill``[#]_ command allows removing a changeset.

Just use hg kill <some-rev>.

[3]kill is a terrible name. NEVER forget to add hg in front of it until we find a better name.

Moving within the history: up gdown and gup

While working on mutable part of the history you often need to move between mutable commit.

You just need to use standard update to work with evolve. For convenience, you can use hg gup to move to children commit or hg gdown to move to working directory parent commit.


those command only exist for the convenience of getting qpush and qpop feeling back.

Collapse changesets: amend

You can use amend -c to collapse multiple changeset in a single one.


This is a terrible UI. hg collapse should be ported to obsolete marker for this purpose.

Split a changeset

There is no official command to split a changeset [3] . However is it easily achieved by manual operation:

### you want to split changeset A: 42
# update to A parent
$ hg up 42^
# restore content from A
$ hg revert -r 42 --all
# partially commit the first part
$ hg record
# commit the second part
$ hg commit
# informs mercurial of what appened
# current changeset (.) and previous one (.^) replace A (42)
$ hg kill --new . --new .^ 42

Update my current work in progess after a pull

Whenever you are working on some changesets, it is more likely that a pull will, eventually, import new changesets in your tree.

And it is likely that you will want your work in progress changesets to be rebased on the top of this newly imported subtree.

Doing so is only a matter of rebasing. Rebase have been wrapped to lay obsolete marker down.

XXX Add an example here.

Move multiple changesets: rebase

You can still use rebase to move a whole segment of the changeset graph together.


Beware that rebasing changesets already obsolete by others will result in conflicting versions of the changesets.

Stabilize history: stabilize

When you rewrite (amend) a changeset with children without rewriting those children you create unstable changesets and suspended obsolete changesets.

When you are finished amending a given changeset, you will want to declare it stable, in other words rebase its former descendants on its newest version. This is not done automatically to avoid the proliferation of useless hidden changesets.


  • hg stabilize have no --continue to use after conflict


  • stabilization does not handle deletion yet.

  • stabilization does not handle rewriting conflict yet.

  • obsolete currently relies on changesets in secret phase to avoid exchanging extinct() changesets.

Fix my history afterward: kill -n

Sometimes you need to create an obsolete marker by hand. This may happen when upstream has applied some of your patches for example.

You can use hg kill --new <new-changeset> <old-changeset> to add obsolete marker.

Export to mq: qsync

Another extension allows to export mutable changeset to mq. See the to enable it and read module documentation for details.

If you do not work at Logilab. You probably do not need it.

View diff from the last amend

An odiff alias have been added by

[alias] odiff = diff --rev 'limit(obsparents(.),1)' --rev .

The qt viewer hgview displays obsolete data and allows to see diff again obsolete parent.

View obsolete markers

hgview is the only viewer that support this feature. You need an experimental version available here:

$ hg clone