- cabal-devel - Haskell.org

cabal-install 3.18.2.0 released
by Francesco Ariis 13 Oct '26

13 Oct '26

The Cabal team is happy to announce the release of `cabal-install` 3.18.2.0 and its related libraries. ## What is new This is a point release, which fixes several bugs in `3.18.1.0`, notably: - `cabal-install` properly cleans temporary files in `/tmp/`. - `Cabal` the library correctly points to `CabalSpecV3_18` as the latest specification. The full changelog for the tool [1] and the libraries [2] are available on GitHub. Read “Known issues” section for regressions still unfixed. [1] https://github.com/haskell/cabal/blob/master/release-notes/cabal-install-3.… [2] https://github.com/haskell/cabal/blob/master/release-notes/Cabal-3.18.2.0.md If you are updating from `3.16`, check the changelogs for `3.18.1.0` too (tool [3], libraries [4]) [3] https://github.com/haskell/cabal/blob/master/release-notes/cabal-install-3.… [4] https://github.com/haskell/cabal/blob/master/release-notes/Cabal-3.18.1.0.md ## Where to get it You can get `cabal-install`: * From our website [5]. The binaries are signed by "Francesco Ariis <fa-ml(a)ariis.it>" (fingerprint: `DAFB 4D8A F684 1435 18D5 051F A9AF 0AAA 6B87 EC51`; the key is hosted on keyserver.ubuntu.com) * From GHCup [6] (“vanilla” channel). * Compiling it yourself with `cabal update && cabal install cabal-install-3.18.2.0`. [5] https://downloads.haskell.org/cabal/cabal-install-3.18.2.0/ [6] https://www.haskell.org/ghcup/ ## Who contributed Code contributions by: Andrea Bedini, Andreas Klebinger, Artem Pelenitsyn, Bodigrim, Curtis Chin Jen Sem, Francesco Ariis, Ilya Baryshnikov, Mikolaj Konarski, Tushar Adhatrao. Many thanks to reviewers, Quality Assurance testers, devops and everyone who made this release possible. ## Feedback For feedback, questions, help, you can find us: * In our GitHub repository [7]. * In our Matrix channel [8]. [7] https://github.com/haskell/cabal/issues [8] https://matrix.to/#/#hackage:matrix.org -- Cabal release team (Artem, Francesco, Ilya, Mikołaj) ## Nightlies Do you want to try new features and help Cabal? Fetch nightlies `cabal-install` snapshots! Get them from GitHub [9] or use `ghcup` invocation below: [9] https://github.com/haskell/cabal/releases/tag/cabal-head ghcup install cabal -u https://github.com/haskell/cabal/releases/download/cabal-head/cabal-head-Li… head

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Seeking feedback on the new cabal-proposals process
by Mikolaj Konarski 26 Jun '25

26 Jun '25

Dear cabal developers and contributors, Please kindly read the proposal for improving the process through which cabal developers introduce and accept cabal design and development decisions at https://github.com/haskell/cabal/pull/11006 and voice your opinion in the linked issue topic. All the best, Mikolaj

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GSoC Project Ideas
by Aaron Allen 24 Jan '25

24 Jan '25

Dear Cabal Devs, We are seeking project ideas for Google Summer of Code 2025! See https://summer.haskell.org/ideas.html for instructions on submitting a project idea, the deadline to submit an idea is Feb 10th. Thanks, Aaron

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Re: Is Cabal a core library?
by Mikolaj Konarski 08 Nov '24

08 Nov '24

Hi Andrew, We discussed this on the list and on today's cabal devs meeting and we are grateful for the proposal and we don't only accept it, but we'd like to ask you to consider all cabal packages (`Cabal`, `Cabal-syntax`, `cabal-install` and `cabal-install-solver`) as core packages. They don't really make much sense without each other and while only two of them are GHC boot packages, if I'm not mistaken, we posit they are all core packages of the Haskell ecosystem. Cheers, Mikolaj On Thu, Nov 7, 2024 at 12:11 AM Andrew Lelechenko <andrew.lelechenko(a)gmail.com> wrote: > > Hi Mikolaj, > > Just a gentle ping, did you come to a conclusion on this? > (I’m not on cabal-devel mail list) > > Best regards, > Andrew > > > On 30 Oct 2024, at 09:03, Mikolaj Konarski <mikolaj(a)well-typed.com> wrote: > > > > In fact, I'm not sure you are on the cabal-devel list, so I should > > have added you to CC of this email. > > > > ---------- Forwarded message --------- > > From: Mikolaj Konarski <mikolaj(a)well-typed.com> > > Date: Wed, Oct 30, 2024 at 9:59 AM > > Subject: Fwd: Is Cabal a core library? > > To: <cabal-devel(a)haskell.org> > > > > > > Andrew, thank you for your kind offer. > > > > Let me forward this to other Cabal developers. > > > > Best regards, > > Mikolaj > > > > ---------- Forwarded message --------- > > From: Andrew Lelechenko <andrew.lelechenko(a)gmail.com> > > Date: Wed, Oct 30, 2024 at 1:50 AM > > Subject: Is Cabal a core library? > > To: Mikolaj Konarski <mikolaj(a)well-typed.com>, Hécate <hecate(a)glitchbra.in> > > > > > > Hi Mikolaj and Hecate, > > > > There is a push to consolidate notions of boot (= needed to build GHC) > > and core (= under CLC aegis) libraries, so that critical parts of > > Haskell ecosystem are more resilient. How do you feel about > > designating `Cabal` and `Cabal-syntax` as core packages? > > > > While at the moment Cabal has a very healthy team (thanks a ton for > > your work!), there were moments in Cabal history when things were > > drastically different. So having an additional safety net, such that > > CLC is able to provide additional / emergency maintenance, could be > > helpful in future. > > > > Designating a library as a core package does not impose much change on > > day-to-day operations. CLC does not interfere with daily development > > of Core Libraries as long as appointed maintainers keep them in an > > appropriate shape and support healthy communication with contributors. > > You can find the full policy at > > https://github.com/haskell/core-libraries-committee?tab=readme-ov-file#core… > > > > (Feel free to forward to other Cabal developers) > > > > Best regards, > > Andrew >

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Re: Your vision for the future of Cabal subsystems
by sebright2 06 Nov '24

06 Nov '24

Here are my main goals for the dependency solver: - Finish implementing per-component dependency solving: https://github.com/haskell/cabal/issues/4087 - Improve performance in the case where there are many dependencies, especially setup and build tool dependencies, but not many conflicts. It would solve issues like https://github.com/haskell/cabal/issues/6309 and make freeze files more useful. - Improve error messages when there is no solution. In simple cases, we might be able to use heuristics (or even an LLM as Artem suggested) to highlight the most important conflicts or suggest solutions. I'd also like the message to focus more on the final conflict set than on the first conflicts encountered, which would help in more complex cases. - Try to find better solutions or make solutions more stable. The solver could also give suggestions on how to improve the solution, such as how to loosen constraints in order to avoid deprecated versions. - Improve documentation of the algorithm. -Kristen > Hi everyone, > > I'd like to ask the people who have been working, are involved or are > dependent on any subsystem of the Cabal project to take some time and think > about what they would like to see for the future. More directly, I would > like to ask you to dream about the future. Don't concern yourself with > implementation, energy or resources, but rather about the direction, and > the shape of the subsystems that you have a stake in. > Things like the solver, the UX of such and such sub-command, performance of > a certain use-case, targeting a certain demographic, a change in how we get > feedback from end-users… > > This will help us with coming up with a product vision that will serve as a > backbone for the immediate and near-future development of cabal. I > understand most of us do this in our free time, but that does not make us > illegitimate to wish for better things, especially when we are involved in > the long run. > > See you all on Matrix and during our bi-monthly meeting. > > Cheers, > Hécate

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Your vision for the future of Cabal subsystems
by Theophile Hécate Choutri 01 Nov '24

01 Nov '24

Hi everyone, I'd like to ask the people who have been working, are involved or are dependent on any subsystem of the Cabal project to take some time and think about what they would like to see for the future. More directly, I would like to ask you to dream about the future. Don't concern yourself with implementation, energy or resources, but rather about the direction, and the shape of the subsystems that you have a stake in. Things like the solver, the UX of such and such sub-command, performance of a certain use-case, targeting a certain demographic, a change in how we get feedback from end-users… This will help us with coming up with a product vision that will serve as a backbone for the immediate and near-future development of cabal. I understand most of us do this in our free time, but that does not make us illegitimate to wish for better things, especially when we are involved in the long run. See you all on Matrix and during our bi-monthly meeting. Cheers, Hécate

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Fwd: Is Cabal a core library?
by Mikolaj Konarski 31 Oct '24

31 Oct '24

Andrew, thank you for your kind offer. Let me forward this to other Cabal developers. Best regards, Mikolaj ---------- Forwarded message --------- From: Andrew Lelechenko <andrew.lelechenko(a)gmail.com> Date: Wed, Oct 30, 2024 at 1:50 AM Subject: Is Cabal a core library? To: Mikolaj Konarski <mikolaj(a)well-typed.com>, Hécate <hecate(a)glitchbra.in> Hi Mikolaj and Hecate, There is a push to consolidate notions of boot (= needed to build GHC) and core (= under CLC aegis) libraries, so that critical parts of Haskell ecosystem are more resilient. How do you feel about designating `Cabal` and `Cabal-syntax` as core packages? While at the moment Cabal has a very healthy team (thanks a ton for your work!), there were moments in Cabal history when things were drastically different. So having an additional safety net, such that CLC is able to provide additional / emergency maintenance, could be helpful in future. Designating a library as a core package does not impose much change on day-to-day operations. CLC does not interfere with daily development of Core Libraries as long as appointed maintainers keep them in an appropriate shape and support healthy communication with contributors. You can find the full policy at https://github.com/haskell/core-libraries-committee?tab=readme-ov-file#core… (Feel free to forward to other Cabal developers) Best regards, Andrew

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Fwd: [ANN] cabal-install-3.12.1.0 (and accompanying libraries) released
by Artem Pelenitsyn 29 Jun '24

29 Jun '24

Dear all, The cabal release team brings you the release of the cabal-install tool, version 3.12.1.0. This is the first release of the tool in the 3.12 series, and, hence, the first cabal-install supporting Cabal 3.12 packaged with GHC 9.10.1. We also update the three main libraries. - cabal-install: The command-line interface for Cabal and Hackage. <https://hackage.haskell.org/package/cabal-install-3.12.1.0> - Cabal: A framework for packaging Haskell software <https://hackage.haskell.org/package/Cabal-3.12.1.0> - Cabal-syntax: A library for working with .cabal files <https://hackage.haskell.org/package/Cabal-syntax-3.12.1.0> - cabal-install-solver: The command-line interface for Cabal and Hackage. <https://hackage.haskell.org/package/cabal-install-solver-3.12.1.0> The binaries for cabal-install are available on our website <https://downloads.haskell.org/cabal/cabal-install-3.12.1.0/> and can be installed via GHCup manually, e.g.: - Linux x86_64 (static, alpine3_18): ghcup --no-cache install cabal -u 'https://downloads.haskell.org/cabal/cabal-install-3.12.1.0/cabal-install-3.…' 3.12.1.0 - MacOS AArch64: ghcup --no-cache install cabal -u 'https://downloads.haskell.org/cabal/cabal-install-3.12.1.0/cabal-install-3.…' 3.12.1.0 - Windows: ghcup --no-cache install cabal -u 'https://downloads.haskell.org/cabal/cabal-install-3.12.1.0/cabal-install-3.…' 3.12.1.0 - or a similar command for your platform using the binaries provided on the website - as usual, cabal update && cabal install cabal-install-3.12.1.0 is an option too. We expect the official GHCup channel to be updated with the 3.12.1.0 binaries soon. <https://discourse.haskell.org/t/cabal-install-3-12-1-0-and-accompanying-lib…>What is new *Performance* - Significant speedups during cabal startup due to use of the latest tar *Project Organization* - Support for asm, cmm, and js sources in executable components - Support for per-component builds when coverage is enabled - Haskell files in explicit source directories take precedence over autogenerated Haskell files - Fix precedence for PATH for build-tools-depends (executables from PATH don’t shadow executables from build-tool-depends anymore) *UX* - Errors now have error codes, which will be documented on https://errors.haskell.org - A new subcommand, cabal path, which can be used to get information about the paths cabal will use within a project - Support for authentication tokens for uploading to Hackage - --(test-)show-details=direct is now the default - Shorten solver rejection messages by removing repetition - Show provenance of project constraints *Interaction with GHC* - Support for loading multiple components into one repl session - Support for the --semaphore flag to enable interaction with GHC Job Server protocol - Support for GHC2024 - Support for language extensions ExtendedLiterals¸ ListTuplePuns, and TypeAbstractions *Other Compilers* - Micro Haskell (MHS) has been added as a known compiler. We don’t have support for driving it yet, though. See the release notes <https://github.com/haskell/cabal/blob/master/release-notes/cabal-install-3.…> for more details and other changes. <https://discourse.haskell.org/t/cabal-install-3-12-1-0-and-accompanying-lib…> Contributors 50^2, Adam Gundry, Andrea Bedini, Andreas Abel, Andreas Klebinger, Arjun Kathuria, Artem Pelenitsyn, BasLaa, Bas Laarakker, Ben Gamari, Bodigrim, Brandon Chinn, brandon s allbery kf8nh, Bryan Richter, Colton Clemmer, Csaba Hruska, cydparser, Daniel Trstenjak, David Binder, David Christiansen, Edwin Marshall, Elodie Lander, Erik de Castro Lopo, Felix Yan, fendor, Finley, Francesco Ariis, Francesco Gazzetta, Fraser Tweedale, Gershom Bazerman, Hamish Mackenzie, Hécate Moonlight, Ikko Eltociear Ashimine, Jana Chadt, Javier Sagredo, Jean-Paul Calderone, Jens Petersen, Jessica Hamilton, John Paul Adrian Glaubitz, Josh Meredith, Julia Longtin, Julian Ospald, Kazuki Okamoto, Kristen Kozak, Krzysztof Gogolewski, liamzee, Liisi Kerik, Lin Runze, Malte Neuss, malteneuss, Marcin Szamotulski, Matthew Pickering, Mel Zuser, Michael Peyton Jones, Mike Pilgrem, Mikolaj Konarski, mixphix, Oleg Grenrus, Ondřej Šebek, Patrick Augusto, Patrick Dougherty, Peter Becich, Phil de Joux, Pierre Le Marre, Rebecca Turner, Rodrigo Mesquita, Ryan Scott, Samuel Thibault, Sander, Sebastian Tee, Sergey Vinokurov, Shae Erisson, sheaf, Simon Hengel, Siyuan Chen, Sören Tempel, SuganyaAK, Suganya Raju, Sylvain Henry, Taylor Fausak, Teo Camarasu, Tom Ellis, tomjaguarpaw, Tommy Bidne, Tom Smeding, Torsten Schmits, Tristan Cacqueray, Troels Henriksen, Wismill, Yvan Sraka, Zoe Zuser We thank all contributors as well as our reviewers, QA testers, devops, and others without whom this release wouldn’t be possible. <https://discourse.haskell.org/t/cabal-install-3-12-1-0-and-accompanying-lib…> Feedback Please, report any issues you notice with the 3.12.1.0 release on our GitHub: https://github.com/haskell/cabal — cabal release team (Artem, Brandon, Francesco, Gershom, Hécate, Mikołaj)

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[ANN] Cabal 3.12 released
by Francesco Ariis 08 May '24

08 May '24

Dear cafe, Cabal team is happy to announce the release of `Cabal` the library version `3.12.0.0` and the companion pre-release of `cabal-install` (the commandline tool; scroll down for more information). ## What is new? There are a number of new features in this release (`Cabal`) and pre-release (`cabal-install`), such as: - Add support for `asm`, `cmm`, and `js` sources in executable components. - Add `--haddock-output-dir` flag to `cabal haddock`. - Add `--semaphore` option to `./Setup build` interface. - Add `--promised-dependency` flag to `./Setup configure` interface. - Add the ability to `--ignore` specific checks to `cabal check`. - Add support for `GHC2024` language edition. - Add support for loading multiple components into one repl session (especially important for HLS users). - Add `cabal path` command. - Add support for authentication tokens for uploading to Hackage. - Allow more flags in the init section of config file. - Add `--semaphore` flag to enable interaction with GHC Job Server protocol. - Adds functionality for the `--offline` flag with the `build` command. - Improve solver rejections in brevity and accuracy. There is much more: for a detailed list of enhancements, changes, and bugfixes, please check the Cabal-3.12.0.0 changelog [1] (and the cabal-install 3.12.0.0-prerelease changelog [2]. [1] https://github.com/haskell/cabal/blob/master/release-notes/Cabal-3.12.0.0.md [2] https://github.com/haskell/cabal/blob/master/release-notes/WIP-cabal-instal… ## Authors and contributors Cabal is a collaborative effort; these people contributed with code to this release: aleeusgr Adam Gundry Andrea Bedini Andreas Abel Andreas Klebinger Arjun Kathuria Artem Pelenitsyn BasLaa Bas Laarakker Ben Gamari Bodigrim Brandon Chinn Brandon S. Allbery Bryan Richter Colton Clemmer Csaba Hruska cydparser Daniel Trstenjak David Binder David Christiansen Edwin Marshall Elodie Lander Erik de Castro Lopo Felix Yan Fendor Finley Francesco Ariis Francesco Gazzetta Fraser Tweedale Gershom Bazerman Hamish Mackenzie Hécate Moonlight Ikko Eltociear Ashimine Jana Chadt Javier Sagredo Jean-Paul Calderone Jens Petersen Jessica Hamilton John Paul Adrian Glaubitz Josh Meredith Julia Longtin Julian Ospald Kazuki Okamoto Kleidukos Kristen Kozak Krzysztof Gogolewski liamzee Liisi Kerik Lin Runze malteneuss Malte Neuss Marcin Szamotulski Matthew Pickering Mel Zuser Michael Peyton Jones Mike Pilgrem Mikolaj Konarski mixphix Oleg Grenrus Ondřej Šebek Patrick Augusto Patrick Dougherty Phil de Joux Pierre Le Marre Rebecca Turner Rodrigo Mesquita Ryan Scott Samuel Thibault Sander Sebastian Tee Sergey Vinokurov Shae Erisson sheaf Simon Hengel Siyuan Chen Sören Tempel Suganya Raju Sylvain Henry Taylor Fausak Teo Camarasu Tom Ellis Tom Smeding Torsten Schmits Tristan Cacqueray Troels Henriksen Wismill Yvan Sraka The release could not be done without the help of the manual QA team and devops people, we thank them both. Thanks also to the many users who provided bug reports and suggestions for improvements. A special mention to Hécate, who recently stepped down from Cabal release coordination and left the process in a better, more organised shape than what was before. ## How to get the `cabal-install` pre-release This release is a Cabal-the-library release, but if you want to test the new features of `cabal-install`, you can download the pre-release of the commandline tool via GHCup. Use one of the following commands, depending on your OS: ghcup --no-cache install cabal -u 'https://gitlab.haskell.org/haskell/cabal/-/jobs/1848320/artifacts/raw/out/c…' 3.12.0.0-prerelease ghcup --no-cache install cabal -u 'https://gitlab.haskell.org/haskell/cabal/-/jobs/1848326/artifacts/raw/out/c…' 3.12.0.0-prerelease ghcup --no-cache install cabal -u 'https://gitlab.haskell.org/haskell/cabal/-/jobs/1848327/artifacts/raw/out/c…' 3.12.0.0-prerelease or an analogous command for any other of the artifacts produced by the [pre-release pipeline](https://gitlab.haskell.org/haskell/cabal/-/pipelines/93759). ## How to help? Cabal is a complex piece of software running on many different machine. Two easy ways to help the development team producing quality releases are: - Join the manual QA team - Test nightly binary `cabal-install` snapshots and pre-releases (such as the 3.12.0.0 pre-release mentioned above) and report any problem you find. [3] https://discourse.haskell.org/t/manual-qa-for-cabal-install/6225

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Re: GSoC mentor for cabal vulnerability check
by Gershom B 08 Mar '24

08 Mar '24

Hi aaron! ccing the cabal-devel list on this. -g On Tue, Mar 5, 2024 at 10:35 AM Aaron Allen <aaronallen8455(a)gmail.com> wrote: > > Hi Gershom, > > I'm looking for a mentor for the cabal vulnerability check project (https://summer.haskell.org/ideas.html#cabal-audit-vulnerable-dependencies) Do you know of anyone who might be willing and able? > > Thanks, > Aaron

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