- ghc-devs - Haskell.org

Building libraries with an in-place GHC
by Simon Peyton Jones 06 Apr '20

06 Apr '20

Devs I want to reproduce #18018, but that needs me to build pandoc with my freshly-built HEAD. I tried this (below) but as you can see that didn't work. What should I do? Thanks Simon bash$ cabal install --with-compiler=/home/simonpj/code/HEAD-3/inplace/bin/ghc-stage2 --package-db=/home/simonpj/code/HEAD-3/inplace/lib/package.conf.d pandoc-2.9.2.1 Resolving dependencies... cabal: Could not resolve dependencies: [__0] trying: pandoc-2.9.2.1 (user goal) [__1] trying: zlib-0.6.2.1 (dependency of pandoc) [__2] trying: base-4.14.0.0/installed-4.14.0.0 (dependency of zlib) [__3] next goal: haddock-library (dependency of pandoc) [__3] rejecting: haddock-library-1.8.0 (conflict: base==4.14.0.0/installed-4.14.0.0, haddock-library => base>=4.7 && <4.14) [__3] skipping: haddock-library-1.7.0, haddock-library-1.6.0, haddock-library-1.5.0.1, haddock-library-1.4.5, haddock-library-1.4.4, haddock-library-1.4.3, haddock-library-1.4.2, haddock-library-1.4.1, haddock-library-1.2.1, haddock-library-1.2.0, haddock-library-1.1.1, haddock-library-1.1.0, haddock-library-1.0.1, haddock-library-1.0.0, haddock-library-1.6.1 (has the same characteristics that caused the previous version to fail: excludes 'base' version 4.14.0.0) [__3] fail (backjumping, conflict set: base, haddock-library, pandoc) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: pandoc, base, haddock-library, zlib Try running with --minimize-conflict-set to improve the error message. bash$ cabal --version cabal-install version 3.2.0.0 compiled using version 3.2.0.0 of the Cabal library

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Module Renaming: GHC.Core.Op
by Andreas Klebinger 06 Apr '20

06 Apr '20

Hello devs, While I looked at the renaming a bit when proposed I only just realized we seem to be using Op as a short name for optimize. I find this very unintuitive. Can we spare another letter to make this GHC.Core.Opt instead? We use opt pretty much everywhere else in GHC already. Cheers Andreas

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Advice implementing new constraint entailment rules
by Matthew Pickering 02 Apr '20

02 Apr '20

Hello, I am attempting to implement two new constraint entailment rules which dictate how to implement a new constraint form "CodeC" can be used to satisfy constraints. The main idea is that all constraints store the level they they are introduced and required (in the Template Haskell sense of level) and that only constraints of the right level can be used. The "CodeC" constraint form allows the level of constraints to be manipulated. Therefore the two rules In order to implement this I want to add two constraint rewriting rules in the following way: 1. If in a given, `CodeC C @ n` ~> `C @ n+1` 2. If in a wanted `CodeC C @ n` -> `C @ n - 1` Can someone give me some pointers about the specific part of the constraint solver where I should add these rules? I am unsure if this rewriting of wanted constraints already occurs or not. Cheers, Matt

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License for grammar
by Евгений Слободкин 01 Apr '20

01 Apr '20

Hi all! I implemented Haskell grammar for ANTLRv4 based on HaskellReport 2010 and GHC source (Parser.y and Lexer.x files). Link: https://github.com/antlr/grammars-v4/blob/master/haskell/Haskell.g4 Could someone please help me figuring out which license this grammar should be published on?

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Re: intent to enable 2fa requirement for github.com/haskell org
by Carter Schonwald 25 Mar '20

25 Mar '20

Duncan, David, please figure out 2fa tools that work for you and enable them, https://github.com/tadfisher/pass-otp https://github.com/solokeys/solo https://github.com/herrjemand/awesome-webauthn#hardware-authenticators https://1password.com/ https://keepass.info/download.html if you are having trouble figuring out tools you're comfortable using, please share with us those constraints we can help you! im here to help (and i'm delaying enabling another day or two to provide help to some active contributors who are having their own difficulties setitng up this stuff) On Wed, Mar 18, 2020 at 6:16 PM Duncan Coutts <duncan(a)dcoutts.me.uk> wrote: > On Wed, 2020-03-18 at 14:46 -0400, Carter Schonwald wrote: > > hey everyone, because so much important stuff for the community, it > > makes sense to add 2fa required for the org, are there any good > > reasons to either wait to do this, or not do it? Feedback welcome! > > I think I might get cut off. > > Is it not still the case that github's 2fa needs a program running on a > mobile phone, or an SMS-capable mobile phone? Is there any support for > normal tools running on a normal Linux machine? > > (I think last time I tried to use the SMS route, it refused to send SMS > messages to my landline, despite the fact that I can receive them) > > > Duncan > >

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Roadmap to compacting ModIface
by Matthew Pickering 25 Mar '20

25 Mar '20

Hello all, I have written down the remaining steps which need to be taken in order to compact a ModIface, which we hope will be useful for applications such as IDEs to reduce GC time. https://gitlab.haskell.org/ghc/ghc/issues/17097#roadmap-to-compacting-a-mod… If there is anyone who wishes to help with this project then please ping me on IRC. So far this is joint work between myself and Daniel G. The first step we need to take is to get 1675 merged which replaces the type backing a FastString from a ByteString to a ShortByteString (and hence from a pinned ByteArray to an unpinned ByteArray). https://gitlab.haskell.org/ghc/ghc/-/merge_requests/1675 Cheers, Matt

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Brief GitLab downtime
by Ben Gamari 22 Mar '20

22 Mar '20

Hi everyone, I'll be rebooting gitlab.haskell.org for a short upgrade. Shouldn't be more than a few minutes. As usual, I'll email when things are back up. Cheers, - Ben

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Getting the inferred types of TH's UnboundVarEs
by Sandy Maguire 20 Mar '20

20 Mar '20

Hi all, I'm writing some TH code that should generate property tests. For example, the expression: $(generate [e| law "idempotent" (insert a (insert a b) == insert a b) |]) should generate the code property $ \a b -> insert a (insert a b) === insert a b I do this by looking for UnboundVarEs in the Exp returned by the [e| quote, and binding them in a lambda. All of this works. However, now I'm trying to get the inferred types of `a` and `b` in the above. GHC clearly is typechecking the quote, since it will fail if I replace `b` with something nonsensical. *Is there some existent way to get the inferred type of an UnboundVarE --- ideally without reimplementing the typechecker?* Thanks! Sandy

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Re: intent to enable 2fa requirement for github.com/haskell org
by Carter Schonwald 19 Mar '20

19 Mar '20

Awesome! After talking with several folks, feedback has been that best practices are to make sure the notice is a week before hand. So what I’ll do is personally reach out to those who aren’t 2fa enabled in the Haskell gh org (and haven’t commented on this thread )and ask them to enable 2fa on their GitHub account. Perhaps I should attach a 2fa options explainer ! I’ll look at folks responses and if everyone active has made the switch over, I’ll look to do a transition next Monday or Tuesday. Be well! (Nyc and many other places are pretty strange right now :/ ) -Carter On Wed, Mar 18, 2020 at 7:42 PM Duncan Coutts <duncan(a)dcoutts.me.uk> wrote: > On Wed, 2020-03-18 at 19:05 -0400, Carter Schonwald wrote: > > No. You don’t. You can use a yubi key and or a totp tool like google > > Authenticator or 1Password etc. no phones required > > It took me a while, but I have successfully managed to turn 2FA back > into 1FA. > > In case it helps anyone else, generate your 2FA response with > > $ oathtool --totp -b $the-2fa-secret > > Where $the-2fa-secret is the code github gives you after the recovery > codes (initially shown as a barcode, but they'll give you the actual > code if you click the link). > > > On Wed, Mar 18, 2020 at 6:16 PM Duncan Coutts <duncan(a)dcoutts.me.uk> > wrote: > > > On Wed, 2020-03-18 at 14:46 -0400, Carter Schonwald wrote: > > > > hey everyone, because so much important stuff for the community, it > > > > makes sense to add 2fa required for the org, are there any good > > > > reasons to either wait to do this, or not do it? Feedback welcome! > > > > > > I think I might get cut off. > > > > > > Is it not still the case that github's 2fa needs a program running on a > > > mobile phone, or an SMS-capable mobile phone? Is there any support for > > > normal tools running on a normal Linux machine? > > > > >

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Re: intent to enable 2fa requirement for github.com/haskell org
by Carter Schonwald 18 Mar '20

18 Mar '20

No. You don’t. You can use a yubi key and or a totp tool like google Authenticator or 1Password etc. no phones required On Wed, Mar 18, 2020 at 6:16 PM Duncan Coutts <duncan(a)dcoutts.me.uk> wrote: > On Wed, 2020-03-18 at 14:46 -0400, Carter Schonwald wrote: > > hey everyone, because so much important stuff for the community, it > > makes sense to add 2fa required for the org, are there any good > > reasons to either wait to do this, or not do it? Feedback welcome! > > I think I might get cut off. > > Is it not still the case that github's 2fa needs a program running on a > mobile phone, or an SMS-capable mobile phone? Is there any support for > normal tools running on a normal Linux machine? > > (I think last time I tried to use the SMS route, it refused to send SMS > messages to my landline, despite the fact that I can receive them) > > > Duncan > >

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