In my view, a lack of communication like the one highlighted here is exactly what the Haskell Foundation hopes to improve. It's still being bootstrapped, so don't expect any action soon, but I would hope for forward motion by the springtime. Of course, the HF needs all of us to be the best foundation it can -- so please consider nominating yourself for a board position (https://haskell.foundation/board-nominations/) and/or applying for the executive director (full-time, salaried) position (https://haskell.foundation/ed-job-description/)! In either role, you could have direct impact on moving this all forward. Richard

On Dec 10, 2020, at 6:42 AM, Allen Sobot via hf-discuss wrote:

As a still (very) new Haskell user by many measures, indeed the little experience I had with Cabal isn't great overall in my view (honestly not a fan of Stack grabbing separate GHC instances though either unless I pass like 2 command-line flags, if there's a configuration option I'm not aware of I'd be grateful).

I had no clue about the communication issues etc. plaguing Cabal, that explains a bit...

In any case I'd like to try to contribute what I can to this effort, mainly to improve the UX which I agree is absolutely terrible in my humble opinion.

(Side note: I was informed on another mailing list that I may have some setting pertaining to forcing some kind of read receipt which is considered impolite on mailing lists, if this is still the case I apologize and I'm trying to determine what even is the precise issue or setting controlling it, at least on K-9 Mail and Neomutt)

On December 10, 2020 12:23:42 p.m. GMT+01:00, Ignat Insarov mailto:kindaro@gmail.com> wrote:

...

# Do something about Cabal?

Hello.

Cabal is the second most used tool in Haskell after GHC. It has many problems. It may be noticed that there is one and a half developers working on it. This is clearly not enough to address these problems. I propose that this is a good place to invest in.

### Problems I have in mind:

* Poor communication, lack of open source development process.

The whole Cabal–Stack schism appears to be an outcome of poor communication. One of the leading developers of Cabal is even banned from participation somewhere in Stack circles.[1] Personally, I reported several issues to Cabal and every single time it resulted in sadness. Observe a vicious circle: core developers are overworked ⇒ they are being unfriendly ⇒ there are fewer contributors ⇒ core developers are overworked.

I have no hard evidence but it appears that presently, more people that strive to improve the Haskell build experience are outside the Cabal cabal than are inside.

* User experience is an afterthought.

Cabal's user experience is horrifying. A collection of complaints is being compiled elsewhere.[2] There are also bugs being opened to Cabal because of this, requiring triage and therefore wasting the precious time of the few overworked developers. Stack is much more friendly — this shows by example that the user experience problem is not inherent and may be solved.

It is ordinary to receive output like this:

``` % cabal run example-executable Warning: The package list for 'hackage.haskell.org' is 84 days old. Run 'cabal update' to get the latest list of available packages. Resolving dependencies... cabal: Could not resolve dependencies: [__0] trying: example-0.1.0.6 (user goal) [__1] next goal: opaleye (dependency of example) [__1] rejecting: opaleye-0.7.1.0, opaleye-0.7.0.0 (constraint from project config TODO requires ==0.6.7006.1) [__1] rejecting: opaleye-0.6.7006.1 (conflict: example => opaleye^>=0.7) [__1] skipping: opaleye-0.6.7006.0, opaleye-0.6.7005.0, opaleye-0.6.7004.2, opaleye-0.6.7004.1, opaleye-0.6.7004.0, opaleye-0.6.7003.1, opaleye-0.6.7003.0, opaleye-0.6.1.0, opaleye-0.6.0.0, opaleye-0.5.4.0, opaleye-0.5.3.1, opaleye-0.5.3.0, opaleye-0.5.2.2, opaleye-0.5.2.0, opaleye-0.5.1.1, opaleye-0.5.1.0, opaleye-0.5.0.0, opaleye-0.4.2.0, opaleye-0.4.1.0, opaleye-0.4.0.0, opaleye-0.3.1.2, opaleye-0.3.1, opaleye-0.3, opaleye-0.2, opaleye-0.6.7002.0, opaleye-0.6.7001.0, opaleye-0.6.7000.0, opaleye-0.5.2.1, opaleye-0.3.1.1 (has the same characteristics that caused the previous version to fail: excluded by constraint '^>=0.7' from example) [__1] fail (backjumping, conflict set: example, opaleye) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: opaleye, example ```

There are so many things that are wrong here. Even a sneaky _«to do»_ remark. If you wonder, in this case the solution is to remove and re-generate `cabal.project.freeze`.

Even the name of the program — it is actually _«cabal-install»_ — is incomprehensible, it should be re-branded to Cabal, which is how everyone calls it anyway.

* Features are not being introduced.

There is no reason for two build tools to exist. The killer feature of Stack — snapshots — should be supported by Cabal. Possibly Cabal itself should be refactored and split so that there are separate tools for packaging, version resolution and human interaction — I do not know. But certainly the way things are presently is a waste of developer effort and a source of confusion for everyone.

### My proposition, in particular.

* Ask all the people that show compassion to the cause of a great Haskell build tool to unite and work together on a better Cabal. This includes the developers of Stack and everyone that expressed unhappiness with the current state of Cabal. These people should be seen as a blessing, not as an obstacle. * Put in place a clear process for contributing and decision making, so that it does not come down to the privileged opinion of one of the core developers. * Make a model of user experience that Cabal should conform to, and make conformance a priority. Surely there are among us people that know a thing or two about user experience — call for them to step forward. Every issue that stems from misunderstanding, re-assign to the model instead of closing. * Merge the support of Stackage snapshots into Cabal. Ask the core developers of Stack to join the effort. Transition from Stack to Cabal should be one well discoverable command that just works.

I realize that this letter is largely an opinion piece. You can also see it as an _«ideal piece»_. Without an ideal, without a vision, we are stuck with the present. I do not insist that my vision is the best. But the present reality is not the best vision either. I propose, foremost, that we work and fight for a better future.

[1]: https://github.com/commercialhaskell/stackage/issues/4472 [2]: https://github.com/tomjaguarpaw/tilapia/issues?q=is%3Aissue+is%3Aopen+cabal _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

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What's wrong with Stack though? Works like a charm in all our projects, and with Nix integration takes care of the external c-libs etc dependencies quite nicely. On Thu, Dec 10, 2020 at 3:07 PM Ignat Insarov wrote:

Thanks Francesco. I have also been using Cabal since a long time ago. There is no question that some great things get done in Cabal. Mostly, Cabal does what it says on the box, and this is why I propose to improve it and not, say, move to Stack. But you may see that many people prefer the latter — this seems even more weird since, as you illuminate, Cabal can already interoperate with Stackage, so it is strictly more featureful. _(As far as I follow, Stack still has poor support for Backpack and sub-package build targets.)_

However, even in the light of the links you provide, we still cannot say that Cabal supports Stackage. You say:

...

...

There is no reason for two build tools to exist. The killer feature of Stack — snapshots — should be supported by Cabal.

As far as I know, this is already possible today! [1]

[1] https://github.com/fpco/stackage-server/issues/232 see also https://github.com/erikd/jenga/ https://hackage.haskell.org/package/stack2cabal

Heading to that link, the closing message says:

...

I've added a warning about the lack of support for revisions in cabal.config in f9632d7. Closing.

So, something is not working. Reading in more detail, there is evidently a disagreement between the core developers of Cabal and Stack. And as I understand, it has not been addressed ever since! This is exactly an example of the kind of communication problems that I alluded to in my first letter. Also, as far as I can see, there has been zero effort from the Cabal team to integrate these other tools that you point to. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

Just my 2 cents of thoughts, no tool can be perfect, as human individuals. If the Haskell ecosystem can be considered a public asset of all users, contributors, it is not wise for us as the stakeholders to be adverse of competition. Just imagine the government allowing a single military contractor to monopolize a whole category of weapons, what would come after? Innovation and advancing comes after competition, why shouldn't we embrace that wrt the tooling of Haskell? Duplication in efforts is a relative smaller problem IMHO. Sincerely, Compl

On 2020-12-11, at 05:07, Jack Kelly via Haskell-Cafe wrote:

Both tools have deficiencies, but looking at the "10 year overnight success" that is the recent step-change in the quality of Haskell's Language Server Protocol support, I am hopeful for the future. The answer is not as simple as "just use stack" or "just use cabal-install". I do not want to kick off a build-tool flamewar, but neither cabal-install nor stack are magical Christmas lands where everything is perfect. Here are a collection of objections to/my frustrations with stack, which is why "just use stack" isn't an answer to the problem:

- Can't do GHCjs - Seems to like mass-rebuilding my work projects if I breathe on them the wrong way - Has its own way of doing everything that's slightly different (different command set, different ways of specifying build targets) - Fails to give me a REPL if it can't load all of a target's files first (I'm not sure exactly what's going on here, but when using dante, stack will blow up if the project contains a type error somewhere. Which is unhelpful when trying to get interactive editor support to resolve said type errors! Dante driving cabal does not have this problem. Extremely frustrating.) - Haskell programmers tend to end up coding to the lowest common subset of features across build tools. This held back adoption of backpack, which is sad. - hpack-by-default pushes another reinvention of basic haskell tooling, and does so with YAML, which is a file format that gets worse the more you understand it. (I expect its defenders will say this is just providing an option, but from my experience onboarding new Hackage uploaders, many people do not realise that hpack is optional.) - Many stack projects do not provide bounds on dependencies, relying on getting exact versions from LTS. This may be defensible for applications that sit at the leaves of a dependency graph, but less so for libraries. Accurate bound information is one of the reasons LTS build plans can be easily constructed, and tooling that encourages sloppy bounds feels to me like it encourages taking without giving back to the shared resource (the common set of libraries on Hackage with well-understood bounds). - What is casa.fpcomplete.com, and why was its downtime causing CI failures in my projects? What does stack talk to that domain about?

HTH,

-- Jack

December 11, 2020 12:17 AM, "J Ho via hf-discuss" wrote:

...

What's wrong with Stack though? Works like a charm in all our projects, and with Nix integration takes care of the external c-libs etc dependencies quite nicely.

On Thu, Dec 10, 2020 at 3:07 PM Ignat Insarov wrote:

...

Thanks Francesco. I have also been using Cabal since a long time ago. There is no question that some great things get done in Cabal. Mostly, Cabal does what it says on the box, and this is why I propose to improve it and not, say, move to Stack. But you may see that many people prefer the latter — this seems even more weird since, as you illuminate, Cabal can already interoperate with Stackage, so it is strictly more featureful. _(As far as I follow, Stack still has poor support for Backpack and sub-package build targets.)_

However, even in the light of the links you provide, we still cannot say that Cabal supports Stackage. You say:

...

...

There is no reason for two build tools to exist. The killer feature of Stack — snapshots — should be supported by Cabal.

As far as I know, this is already possible today! [1]

[1] https://github.com/fpco/stackage-server/issues/232 see also https://github.com/erikd/jenga/ https://hackage.haskell.org/package/stack2cabal

Heading to that link, the closing message says:

...

I've added a warning about the lack of support for revisions in cabal.config in f9632d7. Closing.

So, something is not working. Reading in more detail, there is evidently a disagreement between the core developers of Cabal and Stack. And as I understand, it has not been addressed ever since! This is exactly an example of the kind of communication problems that I alluded to in my first letter. Also, as far as I can see, there has been zero effort from the Cabal team to integrate these other tools that you point to. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

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The correct URL to the up-to-date cabal user guide, since a couple of years ago or more, is: cabal.readthedocs.io In principle, someone could and should make a copy at www.haskell.org/cabal, but I don't know why it hasn't happened. Would be nice. cabal sandboxing is being phased out. Every blog on cabal sandboxing is out of date by definition. Don't bother. If your version of cabal-install is >= 3.0, when you issue "build" "run" etc they already mean v2-build, v2-run, etc. I refer you to the correct up-to-date cabal user guide, chapter 5 "nix-style local builds", for its model. I would not recommend spending time on the v1 model, unless you're a historian. "new-" was a transitional alias to "v2-" during a past transitional period that can be safely ignored (unless you're a historian). (Historians will remind me that the plan was, one day in the future, when the cabal devs introduce a 3rd model, the "new-" prefix will be revived again, this time aliasing to the 3rd model. I say that people are so happy with the current 2nd model that it won't happen.) On 2020-12-11 4:31 a.m., Immanuel Litzroth wrote:

I found the whole cabal experience confusing and not well documented. I kept finding blogs online that were not working anymore in my version of cabal ('cabal sandbox init', 'cabal init --sandbox'...) when looking for advice. I still don't understand the whole v1-build, v2-build, new-build and build... The manual doesn't seem to have a decent conceptual overview of what the tool should do (e.g. an explanation of what sandboxing is supposed to achieve, or the 4 build command versions). Several of the links on this page https://www.haskell.org/cabal/ are dead https://www.haskell.org/cabal/release/cabal-latest/doc/API/Cabal/ or refer to old versions: https://wiki.haskell.org/Upgrading_packages

This should not be construed as a critique of what has been achieved, but as honest feedback of my experience.

...

Innovation and advancing comes after competition, why shouldn't we embrace that wrt the tooling of Haskell? Duplication in efforts is a relative smaller problem IMHO. Well the competition has "go build" and cargo... And duplication of effort is a problem when there's not enough resources for even one decent build tool Immanuel

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Thanks, Ignat for bringing this issue! This is indeed a problem in the Haskell community and ecosystem at the moment, and we can't just ignore it if we want to improve things. Every Haskell developer uses the build tool. This is a crucial piece of development toolchain. That's why it's sad if a core tool is maintained only by a single person, maintainers are not willing to have more open-minded discussions regarding some user-requested features or a tool have poor UX. In my vision, everyone should be welcome to open issues to a build tool and contribute to it as everyone will benefit from improvements. And it's a pity that some people have a negative experience with this process which drives contributors away. I'm following the Cabal issue tracker, so I notice from time to time some not friendly behaviour towards its users. In the same spirit, having multiple build tools leads to duplication of effort for fixing the same problems and implementing the same features. Writing a build tool requires a colossal amount of effort and time. Not to mention that supporting both build tools is an enormous job as well. * If your project builds with Cabal, it's not guaranteed to build with Stack (at least you need to write stack.yaml). * If your project builds with Stack, it's not guaranteed to build with Cabal (you may need to specify upper and lower bounds). Thus, every maintainer must spend a lot of time maintaining support for both build tools if they want to provide good UX for everyone. I'm doing this for multiple years, and it's a troublesome process, but I do believe that thinking about users first is the way forward. This effort seems redundant in a theoretical world where Haskell has a single, core, official, open-sourced build tool managed by the community.

I have enjoyed using cabal very much

I'm also using Cabal for my personal projects, but this doesn't mean there are no problems. I learned to circumvent build tools pitfalls and survive in the ocean of incomprehensible errors, but I'm already in the middle of the ocean, and I don't want to stop swimming. Beginners, who are just staying on the coast, might not want to go into it at all. Best, Dmitrii On Thu, 10 Dec 2020 at 14:06, Ignat Insarov via hf-discuss < hf-discuss@haskell.org> wrote:

Thanks Francesco. I have also been using Cabal since a long time ago. There is no question that some great things get done in Cabal. Mostly, Cabal does what it says on the box, and this is why I propose to improve it and not, say, move to Stack. But you may see that many people prefer the latter — this seems even more weird since, as you illuminate, Cabal can already interoperate with Stackage, so it is strictly more featureful. _(As far as I follow, Stack still has poor support for Backpack and sub-package build targets.)_

However, even in the light of the links you provide, we still cannot say that Cabal supports Stackage. You say:

...

...

There is no reason for two build tools to exist. The killer feature of Stack — snapshots — should be supported by Cabal.

As far as I know, this is already possible today! [1]

[1] https://github.com/fpco/stackage-server/issues/232 see also https://github.com/erikd/jenga/ https://hackage.haskell.org/package/stack2cabal

Heading to that link, the closing message says:

...

I've added a warning about the lack of support for revisions in cabal.config in f9632d7. Closing.

So, something is not working. Reading in more detail, there is evidently a disagreement between the core developers of Cabal and Stack. And as I understand, it has not been addressed ever since! This is exactly an example of the kind of communication problems that I alluded to in my first letter. Also, as far as I can see, there has been zero effort from the Cabal team to integrate these other tools that you point to. _______________________________________________ hf-discuss mailing list hf-discuss@haskell.org https://mail.haskell.org/cgi-bin/mailman/listinfo/hf-discuss