I find the automatic squashing to rather harmful to the commit history.
So if you have several nice commits that you want to send for review,
don't use arc land to commit them, as it will ruin the history. Instead
git push them as per normal and use `arc close` (IIRC) to close the code
review. I also find it useful to remove lots of the arc gunk that was
added to the commit message, to not pollute our revision history with
data from some specific tool.
On Tue, Jun 24, 2014 at 4:09 PM, Richard Eisenberg <[email protected]
<mailto:[email protected]>> wrote:
Thanks so much for writing this! I have some questions:
1) I'm just setting things up on my machine. It says to `arc
install-certificate` in my GHC directory. Is it important precisely
which clone of GHC my directory is set up against? For example, my
"pull" origin is git://git.haskell.org/ghc.git
<http://git.haskell.org/ghc.git> and my "push" origin is
ssh://[email protected]/ghc.git
<http://[email protected]/ghc.git>. Is this the right set-up? If
this bit matters, could you add it to the page? Or, if not, could
you comment on what `arc` is pulling from the ghc directory?
2) I'm confused about what, precisely, `arc diff` does. You describe
that it updates the review available online. Does that reference
some git commits? Do I need to push by `wip` branch before `arc
diff`ing? Do I *never* need to push my branch, because `arc diff`
pushes it for me? Do I *never* need to push my branch, because Phab
uses other ways of moving the code around? For better or worse, I
tend to keep my branches local until I'm ready to merge with master,
and I want to know if this needs to change.
3) You say "A change cannot be merged until at least one reviewer
has signed off." Does this mean "merged with ghc-7.8" (or whatever
the current stable branch is)? Or does it mean "merged with master"?
The former is the status quo, but with a new route, so to speak. The
latter is something new, as several of us push directly to `master`
without a review. I'm not against such a change, per se, just trying
to understand it.
4) Is it now compulsory to use Phab when contributing? This page
makes it sound that way. Again, no complaints -- just trying to
understand it.
5) The page says to add `austin` as a reviewer. I would expect
`thoughtpolice`. What's up with Phab usernames? Do other people I
know and love have Phab usernames distinct from Trac usernames?
6) Who is the reviewer `#ghc`? Is this related to the IRC channel?
What does the # signify?
7) I'm baffled by "Landing reviews". The `arc land` bit is clearer,
but I'm still unsure of what my local state and the git upstream
state must be beforehand for this to work. Will this ask me for a
commit message? Will it use the one I specified to Phab during `arc
diff`? In general, I'm confused about how much info `arc` pulls from
various places to do its work. I know I could learn by doing, but
I'm afraid of mashing on the Phab and/or git history as I do so.
8) Some of the same questions surround `arc patch`: What does my git
state need to be for this to work?
9) How do I contribute to others' revisions? Or, will this be
obvious what it comes to pass?
I realize I've asked a lot here, and it might be too much to expect
all of these answers to be on the page. If that's the case, could
you perhaps link to relevant manuals or places to learn more? The
way `arc` works, in particular, seems like magic; magic is very
powerful, but it can be equally dangerous, and so I'd like to learn
more.
Thanks so much for doing all this!
Richard
On Jun 23, 2014, at 10:44 AM, Austin Seipp <[email protected]
<mailto:[email protected]>> wrote:
> Hi all,
>
> I went ahead and took some time to write some stuff down about
> Phabricator, including some basic tips on the workflows and
> applications here:
>
> https://ghc.haskell.org/trac/ghc/wiki/Phabricator
>
> It's definitely going to need more expanding. Do let me know if
> anything is confusing.
>
> On Wed, Jun 18, 2014 at 2:38 AM, Jan Stolarek
<[email protected] <mailto:[email protected]>> wrote:
>> Duh, ignore what I wrote. I just realized I'm working on a
non-rebased branch :-)
>>
>> Janek
>>
>> Dnia środa, 18 czerwca 2014, Jan Stolarek napisał:
>>> I read the friendly Arcanist manual and I wonder if we intend
to have a
>>> default .arcconfig file in the GHC repo? From the docs it seems
like a good
>>> idea.
>>>
>>> Janek
>>>
>>> Dnia wtorek, 17 czerwca 2014, Simon Marlow napisał:
>>>> On 13/06/14 10:47, Jan Stolarek wrote:
>>>>> It seems that most people are in favour of using Phabricator
for code
>>>>> review. So what are the next steps? Can we just start using the
>>>>> existing phabricator instance? I'm working on some code right
now that
>>>>> definitely needs reviewing.
>>>>
>>>> You can use it, and a few of us have already been doing so.
There isn't
>>>> any Trac integration yet, but it works nicely for patch review.
>>>>
>>>> There's a short intro doc here:
>>>>
https://secure.phabricator.com/book/phabricator/article/differential/,
>>>> but it's not hard to figure out the basics, and you'll learn
by watching
>>>> how other people use it. If you go to the Herald tool you
have yourself
>>>> automatically subscribed to diffs that touch areas of the code
that
>>>> you're interested in.
>>>>
>>>> Pro tip: the keyboard shortcuts are really useful, especially
"z". Hit
>>>> "?" to see all the shortcuts.
>>>>
>>>> Cheers,
>>>> Simon
>>>>
>>>>> Janek
>>>>>
>>>>> Dnia niedziela, 8 czerwca 2014, Simon Marlow napisał:
>>>>>> On 07/06/2014 07:21, Manuel M T Chakravarty wrote:
>>>>>>> So, why not put everything on GutHub and use pull requests
and so on?
>>>>>>
>>>>>> github just isn't great for doing code reviews. No
side-by-side diffs,
>>>>>> and it sends you a separate email for every single comment,
there's no
>>>>>> concept of a "review" consisting of multiple inline comments
(unless
>>>>>> I've missed something). I'm afraid if we were using this for
regular
>>>>>> reviews I would have to disable the email notifications,
which makes
>>>>>> it significantly less useful.
>>>>>>
>>>>>>> SimonM writes that Phabricator is better than GitHub. I’m
happy to
>>>>>>> believe that, but he also writes that using it requires
installing
>>>>>>> local software and quite a bit of work. Moreover, I like to
add that
>>>>>>> lots of people already know how to use GitHub and probably
few know
>>>>>>> Phabricator.
>>>>>>>
>>>>>>> So, we are talking about having a somewhat better tool in
return for
>>>>>>> three very significant disadvantages: (1) local
installation, (2)
>>>>>>> work to set up and maintain Phabricator, and (3) effort by many
>>>>>>> people to learn to use it.
>>>>>>
>>>>>> Well, you've tipped the balance with "somewhat" and
"significant"
>>>>>> here, I'd say Phabricator is "significantly" better than
github for
>>>>>> code reviews, while installing arc is "somewhat" annoying :-)
>>>>>>
>>>>>> I have to admit it's not a no-brainer, but I do worry that
github just
>>>>>> wouldn't cut it for doing a lot of code reviewing, whereas I
spend my
>>>>>> life inside Phabricator so I know it works really well.
>>>>>>
>>>>>> What's more, github doesn't let you put animated gifs in
code reviews.
>>>>>> Need I say more?
>>>>>>
>>>>>> Cheers,
>>>>>> Simon
>>>>>>
>>>>>>> We also have a constant lack of sufficient men power. So,
why spend
>>>>>>> effort on building our own infrastructure, which will only
increase
>>>>>>> the hurdle for contributors (as they have to deal with an
unknown
>>>>>>> system)? Let’s outsource the effort to GitHub.
>>>>>>>
>>>>>>> Manuel
>>>>>>>
>>>>>>> Simon Peyton Jones <[email protected]
<mailto:[email protected]>>:
>>>>>>>> At the moment GHC's main sources aren't on github, which
means that
>>>>>>>> that (in my highly imperfect understanding) people can't
submit pull
>>>>>>>> requests or use their code review mechanisms. Moreover,
most people
>>>>>>>> don't have commit rights on the main GHC server, so if
someone wants
>>>>>>>> to offer a patch they can really only do so in textual
form attached
>>>>>>>> to Trac. People with commit rights can make a branch, but
there's a
>>>>>>>> danger that over a decade we'll accumulate zillions of
dead branches
>>>>>>>> which people forgot to delete. I think on github the
branch is in a
>>>>>>>> different repo, belonging to the patch author.
>>>>>>>>
>>>>>>>> So we really don't have a good work flow for creating,
reviewing,
>>>>>>>> modifying, and finally apply patches. I am no expert on these
>>>>>>>> matters. If Phabricator would help with that I'm all for
it. But
>>>>>>>> perhaps there are other alternatives? Or is Phab the lead
thing.
>>>>>>>> Will it stay around?
>>>>>>>>
>>>>>>>> Also before going too far I'd really like someone to
document the
>>>>>>>> workflow carefully, and make sure it works from Windows
equally
>>>>>>>> well.
>>>>>>>>
>>>>>>>> I'm not too stressed out about losing the review trail of
a patch.
>>>>>>>> Much of it will be commenting on stuff that no longer
appears in the
>>>>>>>> final patch. Anything that's important should appear in a
Note in
>>>>>>>> the source code; even the commit messages are invisible
until you
>>>>>>>> really start digging.
>>>>>>>>
>>>>>>>> Simon
>>>>>>>>
>>>>>>>> | -----Original Message-----
>>>>>>>> | From: ghc-devs [mailto:[email protected]
<mailto:[email protected]>] On Behalf Of
>>>>>>>> | Austin Seipp
>>>>>>>> | Sent: 06 June 2014 05:06
>>>>>>>> | To: [email protected] <mailto:[email protected]>
>>>>>>>> | Subject: RFC: Phabricator for patches and code review
>>>>>>>> |
>>>>>>>> | Hello all,
>>>>>>>> |
>>>>>>>> | Recently, while doing server maintenance, several of the
>>>>>>>> | administrators for Haskell.org set up an instance of
>>>>>>>> | Phabricator[1], located at https://phabricator.haskell.org
>>>>>>>> |
>>>>>>>> | For those who aren't aware, Phabricator (or "Phab") is a
suite of
>>>>>>>> | tools for software development. Think of it like a polished,
>>>>>>>> | semi-private GitHub with a lot of applications and tools
for all
>>>>>>>> | kinds of needs. We've been using it to do issue tracking for
>>>>>>>> | Haskell.org maintenance and like it a lot so far.
>>>>>>>> |
>>>>>>>> | One very nice aspect of Phabricator though is it has a
very nice
>>>>>>>> | code review tool, called 'Differential', that is very
useful. For
>>>>>>>> | people who have used a tool like Review Board, it's similar.
>>>>>>>> | Furthermore, it has a very convenient userland tool called
>>>>>>>> | 'Arcanist' which makes it easy for newcomers to post a
review and
>>>>>>>> | get it merged when it's ready all from the command line.
>>>>>>>> |
>>>>>>>> | I'd like to see if people are interested in using Phab
_strictly_
>>>>>>>> | for code review of GHC patches. It is a dedicated tool
>>>>>>>> | specifically for this, and I think it works much better
than Trac
>>>>>>>> | or inline GitHub comments.
>>>>>>>> |
>>>>>>>> | Also, Phab can also support post-commit reviews. So if I
touch
>>>>>>>> | something in the runtime system and just push, perhaps
Simon or
>>>>>>>> | Edward would like to look, and they can be alerted right
when I do
>>>>>>>> | this, and then yell if I did something stupid.
>>>>>>>> |
>>>>>>>> | Before I go much further, I'd like to ask: is there
*any* interest
>>>>>>>> | in this? Or are people satisifed with Trac? The primary
>>>>>>>> | motivations are roughly, in no particular order:
>>>>>>>> |
>>>>>>>> | 1) Code review is good for everyone, a good way for
people to
>>>>>>>> | learn the code and ask questions, and useful to give
feedback to
>>>>>>>> | newcomers. And even experienced GHC hackers can learn
things from
>>>>>>>> | reading code, as we all do regularly, or find things
that need
>>>>>>>> | cleanup.
>>>>>>>> |
>>>>>>>> | 2) Phabricator in particular makes it very easy to
submit patches
>>>>>>>> | for review. To submit a patch, I just run the command
'arc diff'
>>>>>>>> | and it Does The Right Thing. It also makes it easy to ensure
>>>>>>>> | people are *alerted* when a patch might be relevant to them.
>>>>>>>> |
>>>>>>>> | 3) They can be uploaded and created from the command
line, and
>>>>>>>> | merged easily afterwords the same way. This is
particularly useful
>>>>>>>> | for newcomers, and for me. :)
>>>>>>>> |
>>>>>>>> | 4) Differential is dedicated to code review, and much
better at
>>>>>>>> | it than just reading patches on Trac IMO.
>>>>>>>> |
>>>>>>>> | 5) It supports both post-commit code review, as well as
>>>>>>>> | pre-commit review. Post commit would be especially
useful for us
>>>>>>>> | too, I think.
>>>>>>>> |
>>>>>>>> | Point #2 and #3 are mostly relevant for me, because I mostly
>>>>>>>> | handle incoming patches. But I think in general it would
be nice,
>>>>>>>> | and make it a lot easier for newcomers to submit
patches, and us
>>>>>>>> | to look over them.
>>>>>>>> |
>>>>>>>> | Here's an example of a Differential code review:
>>>>>>>> |
>>>>>>>> | https://phabricator.haskell.org/D4
>>>>>>>> |
>>>>>>>> | This is a demo using my 'wip/ermsb' patch. You'll need
to create
>>>>>>>> | an account to login, but it shouldn't be much trouble,
you can
>>>>>>>> | login several ways. I'll fix the login requirement soon.
Feel free
>>>>>>>> | to read the code, comment on it, and play around. It's
more of a
>>>>>>>> | demonstration, but real code review would be welcome too. :)
>>>>>>>> |
>>>>>>>> | If people are interested in doing this, I can add notes
to the
>>>>>>>> | wiki pages for newcomers, and I'll send another email
about Phab
>>>>>>>> | so people can understand it a little better. But I want
to ask
>>>>>>>> | first.
>>>>>>>> |
>>>>>>>> | There is an argument that our team is so small, code
review has
>>>>>>>> | unnecessary burdens. But I think Phab could help a lot with
>>>>>>>> | tracking outside patches and getting good reviews for
incoming
>>>>>>>> | patches, and it'll make it easier for newcomers. And
experienced
>>>>>>>> | pros can probably learn a thing as well.
>>>>>>>> |
>>>>>>>> | Again, to be clear, I don't propose we migrate anything to
>>>>>>>> | Phabricator from, say, Trac. There's no real pressure to
do so and
>>>>>>>> | it would be tons of work. I only propose we use it for code
>>>>>>>> | review, which is perfectly fine, and how other projects
like LLVM
>>>>>>>> | do code review (they use Bugzilla).
>>>>>>>> |
>>>>>>>> | I also don't think the usage of Phabricator should be
mandatory
>>>>>>>> | (unless we decide that later because we like it), but I
would like
>>>>>>>> | to see people use it if possible.
>>>>>>>> |
>>>>>>>> | [1] http://phabricator.org
>>>>>>>> |
>>>>>>>> | --
>>>>>>>> | Regards,
>>>>>>>> |
>>>>>>>> | Austin Seipp, Haskell Consultant
>>>>>>>> | Well-Typed LLP, http://www.well-typed.com/
>>>>>>>> | _______________________________________________
>>>>>>>> | ghc-devs mailing list
>>>>>>>> | [email protected] <mailto:[email protected]>
>>>>>>>> | http://www.haskell.org/mailman/listinfo/ghc-devs
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> ghc-devs mailing list
>>>>>>>> [email protected] <mailto:[email protected]>
>>>>>>>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ghc-devs mailing list
>>>>>>> [email protected] <mailto:[email protected]>
>>>>>>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>>>>>
>>>>>> _______________________________________________
>>>>>> ghc-devs mailing list
>>>>>> [email protected] <mailto:[email protected]>
>>>>>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>>>>
>>>>> _______________________________________________
>>>>> ghc-devs mailing list
>>>>> [email protected] <mailto:[email protected]>
>>>>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>>
>>> _______________________________________________
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>>
>>
>
>
>
> --
> Regards,
>
> Austin Seipp, Haskell Consultant
> Well-Typed LLP, http://www.well-typed.com/
> _______________________________________________
> ghc-devs mailing list
> [email protected] <mailto:[email protected]>
> http://www.haskell.org/mailman/listinfo/ghc-devs
>
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