llvm dev - May 2017 - Add more projects into Git monorepo

> On May 9, 2017, at 9:06 AM, Mehdi AMINI via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> 
> 
> 2017-05-09 9:03 GMT-07:00 David Chisnall <David.Chisnall at cl.cam.ac.uk
<mailto:David.Chisnall at cl.cam.ac.uk>>:
> On 9 May 2017, at 16:59, Mehdi AMINI <joker.eph at gmail.com
<mailto:joker.eph at gmail.com>> wrote:
> >
> > I'm not sure if you really read the last sentence of what I wrote,
or if you followed the previous discussions on the plan here?
> > At this point I believe that this concern is non-existent per the
read-only individual repo.
> 
> The read-only repo is only useful if you don’t intend to contribute stuff
back upstream.
> 
> Your point was about CI...
> (unless you're working on some CI that would fix bugs and send PR?)
>  
> There is no convenient workflow for cloning libunwind / libc++ /
libwhatever, hacking on it, and sending pull requests.
> 
> We considered git-svn for this though.
> 
>  
> 
> > We can leave it there :)
> > There have been extensive discussions, a BoF, and documentations,
please refer you to these first (granted we haven't really talked about
libunwind, but I'm not sure many people will be strongly opposed to
libunwind having its separate life).
> 
> There have been multiple discussions, and the conclusion from all that I
have participated in was that projects that are tightly version locked to LLVM
should be in the monorepo, everything else should be separate.  Apparently there
is now a plan underway to not do this and to make life harder for people who
work on the projects that are not version locked to LLVM.
> 
> We have a different understanding.
I feel like I need to take a minute here to voice my supreme frustration with
the way this discussion has gone and this small sentence captures it entirely.

From beginning to end these git migration conversations have involved a whole
lot of people talking past each other and a lot of assumptions that are not
shared. Many of us are very much not on the same page. The only thing that we
had a significant consensus on was that we'd like to move to GitHub. Other
than that we have more disagreement than agreement.

We do not have consensus on an all-in-one monorepo, and any notion that we do is
ignoring the significant dissent. There was less disagreement with a mono-repo
that had only tightly coupled projects, but that itself is hard to nail down and
define, and there are still many people (myself included) who prefer the
multi-repo solution.

Mehdi, I don't know if it is your intent, but in many places in this thread
you sound as if this decision has been made and the community is fully
supporting your decision. Please don't do that. It would be nice if as a
community we considered the concerns of our members instead of offhand
dismissing them.

I think we should spend some time discussing and understanding the needs of our
corporate contributors and the needs of the other open source projects that
contribute to, use, and distribute LLVM. I believe that disregarding the
concerns of communities like the BSD and Linux communities would be a severe
detriment to the LLVM project.

-Chris
> 
> -- 
> Mehdi
> 
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Hi Chris,

2017-05-10 19:21 GMT-07:00 Chris Bieneman <beanz at apple.com>:
>
> On May 9, 2017, at 9:06 AM, Mehdi AMINI via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>
>
> 2017-05-09 9:03 GMT-07:00 David Chisnall <David.Chisnall at
cl.cam.ac.uk>:
>
>> On 9 May 2017, at 16:59, Mehdi AMINI <joker.eph at gmail.com>
wrote:
>> >
>> > I'm not sure if you really read the last sentence of what I
wrote, or
>> if you followed the previous discussions on the plan here?
>> > At this point I believe that this concern is non-existent per the
>> read-only individual repo.
>>
>> The read-only repo is only useful if you don’t intend to contribute
stuff
>> back upstream.
>
>
> Your point was about CI...
> (unless you're working on some CI that would fix bugs and send PR?)
>
>
>> There is no convenient workflow for cloning libunwind / libc++ /
>> libwhatever, hacking on it, and sending pull requests.
>>
>
> We considered git-svn for this though.
>
>
>
>>
>> > We can leave it there :)
>> > There have been extensive discussions, a BoF, and documentations,
>> please refer you to these first (granted we haven't really talked
about
>> libunwind, but I'm not sure many people will be strongly opposed to
>> libunwind having its separate life).
>>
>> There have been multiple discussions, and the conclusion from all that
I
>> have participated in was that projects that are tightly version locked
to
>> LLVM should be in the monorepo, everything else should be separate.
>> Apparently there is now a plan underway to not do this and to make life
>> harder for people who work on the projects that are not version locked
to
>> LLVM.
>>
>
> We have a different understanding.
>
>
> I feel like I need to take a minute here to voice my supreme frustration
> with the way this discussion has gone and this small sentence captures it
> entirely.
>
>
You'll have to elaborate what is wrong with this sentence, because I'm
basically saying that I disagree there was a consensus or a conclusion on
what goes exactly in the monorepo, which is what David was claiming. I
believe the exact set of projects was punted to future discussions.

I also happen to know that some important stakeholders are strongly against
not having the full toolchain together (i.e. libc++ has to be with clang
for example) and would strongly prefer status quo (and staying on SVN) to
having half of the toolchain together but not as a whole (not that they
necessarily have to have their way, but that's another important weight in
the balance).


> From beginning to end these git migration conversations have involved a
> whole lot of people talking past each other and a lot of assumptions that
> are not shared. Many of us are very much not on the same page. The only
> thing that we had a significant consensus on was that we'd like to move
to
> GitHub. Other than that we have more disagreement than agreement.
>
Sure.


> We do not have consensus on an all-in-one monorepo,
>
Yes. But:
1) We don't have a consensus on anything but "we should go to
GitHub" at
this point.
2) Please acknowledge that the opposite is true as well (which is what my
sentence above what answering to!).

> and any notion that we do is ignoring the significant dissent. There was
> less disagreement with a mono-repo that had only tightly coupled projects,
> but that itself is hard to nail down and define, and there are still many
> people (myself included) who prefer the multi-repo solution.
>
> Mehdi, I don't know if it is your intent, but in many places in this
> thread you sound as if this decision has been made and the community is
> fully supporting your decision. Please don't do that.
>
This is your reading, this is not what I wrote. Please don't
over-interpret. See at the end of this email for a reminder on where I
stand right now.

> It would be nice if as a community we considered the concerns of our
> members instead of offhand dismissing them.
>
The only thing I dismiss is what is not supported by any facts:

Example from this thread: "the CI for libunwind will have to checkout extra
stuff" -> "individual repositories are addressing this".
Unless I have new
extra informations that I can take into account about why the individual
repo are not addressing this specific exact concern, yes you can consider
that I'm dismissive this "concern".
Also, not that expressing a disagreement with your opinion is not the same
thing as dismissing it though, so please don't put everything in the same
bucket. If you have any issue, let's be specific.

>
> I think we should spend some time discussing and understanding the needs
> of our corporate contributors and the needs of the other open source
> projects that contribute to, use, and distribute LLVM. I believe that
> disregarding the concerns of communities like the BSD and Linux communities
> would be a severe detriment to the LLVM project.
>
At this point, I believe I spent a considerable amount of time
discussing/experimenting/prototype/considering scenarios/etc. I don't mean
this to say that I have all the knowledge of all the possible situations,
or that my personal opinion would matter more, but I somehow feel that your
paragraph above is negating the time and energy I made into accumulating
all the elements and engaging in discussions with all possible parties
interested into it.

As a reminder, the current status today and my position is the same as in
January: http://lists.llvm.org/pipermail/llvm-dev/2017-January/109015.html
; which can be summarized as: "At some point, if the experiment is
conclusive, we should be able to build a larger majority and hopefully
reach a consensus that the proposed prototype can be considered viable for
development and start planning the actual committing changes."
There's a lot of uncertainty there, I never announced any
"decision" (which
I never pretended to be in my hands).

See also Chris' answer for a more explicit version:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/109115.html

Best,

--
Mehdi
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Personally, I don't think it is even possible to please everyone.  While I
don't want to ignore the dissent, I also don't want to ignore the fact
that
the dissent *has* been a minority, and I believe there has been more
dissent in *not* adopting monorepo as there has been to adopting monorepo.

Somewhere along the line, someone has to pull the trigger and make a
decision.  There are people who are just as inconvenienced today (which,
btw, has been a lingering inconvenience for many years in some cases) by
*not* having a mono-repo as others would be by having a mono-repo.

Discussions are only meaningful insofar as they contribute something new to
the playing field.  We have had so many discussions, surveys, talks, email
threads, experiments, etc that at this point I honestly don't know how else
to meaningfully contribute something new?

On Wed, May 10, 2017 at 8:36 PM Mehdi AMINI via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi Chris,
>
> 2017-05-10 19:21 GMT-07:00 Chris Bieneman <beanz at apple.com>:
>
>>
>> On May 9, 2017, at 9:06 AM, Mehdi AMINI via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>
>>
>> 2017-05-09 9:03 GMT-07:00 David Chisnall <David.Chisnall at
cl.cam.ac.uk>:
>>
>>> On 9 May 2017, at 16:59, Mehdi AMINI <joker.eph at gmail.com>
wrote:
>>> >
>>> > I'm not sure if you really read the last sentence of what
I wrote, or
>>> if you followed the previous discussions on the plan here?
>>> > At this point I believe that this concern is non-existent per
the
>>> read-only individual repo.
>>>
>>> The read-only repo is only useful if you don’t intend to contribute
>>> stuff back upstream.
>>
>>
>> Your point was about CI...
>> (unless you're working on some CI that would fix bugs and send PR?)
>>
>>
>>> There is no convenient workflow for cloning libunwind / libc++ /
>>> libwhatever, hacking on it, and sending pull requests.
>>>
>>
>> We considered git-svn for this though.
>>
>>
>>
>>>
>>> > We can leave it there :)
>>> > There have been extensive discussions, a BoF, and
documentations,
>>> please refer you to these first (granted we haven't really
talked about
>>> libunwind, but I'm not sure many people will be strongly
opposed to
>>> libunwind having its separate life).
>>>
>>> There have been multiple discussions, and the conclusion from all
that I
>>> have participated in was that projects that are tightly version
locked to
>>> LLVM should be in the monorepo, everything else should be separate.
>>> Apparently there is now a plan underway to not do this and to make
life
>>> harder for people who work on the projects that are not version
locked to
>>> LLVM.
>>>
>>
>> We have a different understanding.
>>
>>
>> I feel like I need to take a minute here to voice my supreme
frustration
>> with the way this discussion has gone and this small sentence captures
it
>> entirely.
>>
>>
> You'll have to elaborate what is wrong with this sentence, because
I'm
> basically saying that I disagree there was a consensus or a conclusion on
> what goes exactly in the monorepo, which is what David was claiming. I
> believe the exact set of projects was punted to future discussions.
>
> I also happen to know that some important stakeholders are strongly
> against not having the full toolchain together (i.e. libc++ has to be with
> clang for example) and would strongly prefer status quo (and staying on
> SVN) to having half of the toolchain together but not as a whole (not that
> they necessarily have to have their way, but that's another important
> weight in the balance).
>
>
>
>> From beginning to end these git migration conversations have involved a
>> whole lot of people talking past each other and a lot of assumptions
that
>> are not shared. Many of us are very much not on the same page. The only
>> thing that we had a significant consensus on was that we'd like to
move to
>> GitHub. Other than that we have more disagreement than agreement.
>>
>
> Sure.
>
>
>
>> We do not have consensus on an all-in-one monorepo,
>>
>
> Yes. But:
> 1) We don't have a consensus on anything but "we should go to
GitHub" at
> this point.
> 2) Please acknowledge that the opposite is true as well (which is what my
> sentence above what answering to!).
>
>
>> and any notion that we do is ignoring the significant dissent. There
was
>> less disagreement with a mono-repo that had only tightly coupled
projects,
>> but that itself is hard to nail down and define, and there are still
many
>> people (myself included) who prefer the multi-repo solution.
>>
>> Mehdi, I don't know if it is your intent, but in many places in
this
>> thread you sound as if this decision has been made and the community is
>> fully supporting your decision. Please don't do that.
>>
>
> This is your reading, this is not what I wrote. Please don't
> over-interpret. See at the end of this email for a reminder on where I
> stand right now.
>
>
>> It would be nice if as a community we considered the concerns of our
>> members instead of offhand dismissing them.
>>
>
> The only thing I dismiss is what is not supported by any facts:
>
> Example from this thread: "the CI for libunwind will have to checkout
> extra stuff" -> "individual repositories are addressing
this". Unless I
> have new extra informations that I can take into account about why the
> individual repo are not addressing this specific exact concern, yes you can
> consider that I'm dismissive this "concern".
> Also, not that expressing a disagreement with your opinion is not the same
> thing as dismissing it though, so please don't put everything in the
same
> bucket. If you have any issue, let's be specific.
>
>
>>
>> I think we should spend some time discussing and understanding the
needs
>> of our corporate contributors and the needs of the other open source
>> projects that contribute to, use, and distribute LLVM. I believe that
>> disregarding the concerns of communities like the BSD and Linux
communities
>> would be a severe detriment to the LLVM project.
>>
>
> At this point, I believe I spent a considerable amount of time
> discussing/experimenting/prototype/considering scenarios/etc. I don't
mean
> this to say that I have all the knowledge of all the possible situations,
> or that my personal opinion would matter more, but I somehow feel that your
> paragraph above is negating the time and energy I made into accumulating
> all the elements and engaging in discussions with all possible parties
> interested into it.
>
> As a reminder, the current status today and my position is the same as in
> January: http://lists.llvm.org/pipermail/llvm-dev/2017-January/109015.html
> ; which can be summarized as: "At some point, if the experiment is
> conclusive, we should be able to build a larger majority and hopefully
> reach a consensus that the proposed prototype can be considered viable for
> development and start planning the actual committing changes."
> There's a lot of uncertainty there, I never announced any
"decision"
> (which I never pretended to be in my hands).
>
> See also Chris' answer for a more explicit version:
> http://lists.llvm.org/pipermail/llvm-dev/2017-January/109115.html
>
> Best,
>
> --
> Mehdi
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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