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Checkout the Last Public Revision with Mercurial

By David Walsh on June 19, 2019

I've always preferred git over Mercurial (hg) because the feature branch workflow makes organizing code and working off of master very easy. You don't get that with vanilla mercurial -- instead, commits can just sort of apply on top of each other, without much organization. Sometimes mercurial can feel a bit chaotic.

When working on Mozilla's mozilla-central repository (for your beloved Firefox!), I always start new commits off of the latest public commit. "public means it has been merged into mozilla-central, "draft" means it was created locally and is only on my machine.

Getting the last public revision ID required a bit of command line hackery and search so I found a better way to check out the last public revision:

hg checkout -r 'last(public())'

That command is a bit much to remember so I created an alias in my .bash_profile:

alias hgmaster='hg checkout -r “last(public())”’

As with every alias I create, whether a git alias or a bash alias, I wish I had created this sooner -- I'd have saved so much time!

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Discussion

Jeremy
What do you mean you can’t use the feature branch workflow with Mercurial?

David Walsh
I guess branches are different with Mercurial, and that bookmarks don’t feel the same as branching off of master. Could just be me.

glob
It would be simpler/quicker to instead do:
```
hg checkout -r 'last(public())'
```

David Walsh
Thank you Glob! Updated!

agentgt
You can also use mercurials excellent revsetalias and alias support:
```
[alias]
master = update -r 'last(public())'

[revsetalias]
master = last(public())
wip = (parents(not public()) or not public() or . or head()) and not closed()
```
Now You can do
```
hg update master
```
or
```
hg master
```
I added the revset alias wip as well which shows the changes you haven’t yet pushed to master.

Finally for lightweight branches I highly recommend the evolve extension and just making normal mercurial named branches that you only push to your local mutable (non publishing repository). So long as the branches are in draft you can delete them which will be the case if the repository is non publishing.