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data families syntax
by Harendra Kumar 13 Nov '16

13 Nov '16

I am curious about why the data families syntax was chosen to be the way it is. For example a list can be defined as follows: data family List a data instance List Char = Empty | Cons Char (List Char) data instance List () = Count Int Instead why not define it as: data List :: * -> * data List Char = Empty | Cons Char (List Char) data List () = Count Int The latter form looks more intuitive and easy to remember to me since it is very similar to the way value level functions are defined (signature & pattern matching defs). Here we are just defining a type level function instead. -harendra

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New home for the perf.haskell.org builder wanted
by Joachim Breitner 12 Nov '16

12 Nov '16

Hi, although I have moved away from Karlsruhe three months ago, so far it is still my office PC driving https://perf.haskell.org/ghc/ But a new person is now using my desk and wants to use this machine, so I should really really move this away from there now. Sebastian Graf has been working on turning gipeda, the Frontend perf.haskell.org, into a more general service open to open source Haskell projects, and this is close, but not close enough to simply stop running the performance tests until he is good to go. He currently has a machine given from haskell.org to run this on, but it is a virtual machine and the measurements are too flaky for real use. So basically, I need a decent non-virtualized (or virtualized, but exclusive) machine to move my performance build runner to, as quickly as possible. The current specs are * 8 core Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz * 16 GB RAM but it does not matter too much, a slightly weaker machine would be able to keep up as well. I also do not necessarily need root access (but it would be beyond the point if the machine would do other stuff that incurs a heavy load). The same machine could then be used by Sebastian for his more general setup, once that is ready to go. Does anyone have something handy? Greetings, Joachim -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • https://www.joachim-breitner.de/ XMPP: nomeata(a)joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F Debian Developer: nomeata(a)debian.org

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177 unexpected test failures on a new system -- is this yet another linker issue?
by Ömer Sinan Ağacan 12 Nov '16

12 Nov '16

I'm trying to validate on a new system (not sure if related, but it has gcc 6.2.1 and ld 2.27.0), and I'm having 177 unexpected failures, most (maybe even all) of them are similar to this one: =====> T5976(ext-interp) 1 of 1 [0, 0, 0] cd "./th/T5976.run" && "/home/omer/haskell/ghc/inplace/test spaces/ghc-stage2" -c T5976.hs -dcore-dno-debug-output -XTemplateHaskell -package template-haskell -fexternal-interpreter -v0 Actual stderr output differs from expected: --- ./th/T5976.run/T5976.stderr.normalised 2016-11-10 23:01:39.351997560 -0500 +++ ./th/T5976.run/T5976.comp.stderr.normalised 2016-11-10 23:01:39.351997560 -0500 @@ -1,7 +1,4 @@ - -T5976.hs:1:1: - Exception when trying to run compile-time code: - bar -CallStack (from HasCallStack): - error, called at T5976.hs:<line>:<column> in <package-id>:Main - Code: error ((++) "foo " error "bar") +ghc-iserv.bin: internal loadArchive: GNU-variant filename offset not found while reading filename f + (GHC version 8.1.20161107 for x86_64_unknown_linux) + Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug +ghc: ghc-iserv terminated (-6) *** unexpected failure for T5976(ext-interp) Does anyone know what is this about?

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Breakage due to CallStack refactoring
by Ben Gamari 11 Nov '16

11 Nov '16

Hi Simon, In 317236db308d you performed some refactoring of CallStack defaulting and noted that there was no change in visisble behavior. However, it isn't seem that this is true. The following two tests [1] now fail as callstacks are no longer produced in their output, TEST="assert T10845" Presumably this isn't expected. Cheers, - Ben [1] https://phabricator.haskell.org/harbormaster/build/14964/?l=100

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install pandoc with cabal update
by CRUMEYROLLE Pierre 10 Nov '16

10 Nov '16

hello y try to install pandoc in mode offline but the standard installation from source preconise to execute cabal update . it seems that cabal update try to connect and download package from hackage.haskell.org. do you known how to execute offline installation ? ghc 7.10.3 cabal 1.24.0.0 best regards

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ppr of HsDo
by Alan & Kim Zimmerman 10 Nov '16

10 Nov '16

The pretty printer turns foo = do let x = 1 Just 5 into foo = do { let x = 1; Just 5 } which does not parse, complaining about "parse error on input ‘Just’" Is this a parser error or a ppr problem? I am keen to fix the ppr to output foo = do let x = 1 Just 5 but I am not sure if there is a parser bug too. Alan

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D2638: Reviewers Needed
by Thomas Jakway 06 Nov '16

06 Nov '16

My first patch to GHC <https://phabricator.haskell.org/D2638> is on Phab and Matthew Pickering suggested I get someone knowledgeable about the register allocator to review it. I checked the Code Owners page <https://ghc.haskell.org/trac/ghc/wiki/CodeOwners> but it's very out of date and doesn't mention the NCG specifically. If anyone here familiar with the backend would care to take a look I would very much appreciate it. Thanks, Thomas Jakway

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Re: Submitting a patch for hsc2hs
by Ryan Scott 04 Nov '16

04 Nov '16

Hi Erik, I'm not sure if the hsc2hs repo [1] has "official" Phabricator integration, but what I did when I submitted a patch to hsc2hs was: 1. Commit your changes 2. Because the hsc2hs repo doesn't have an .arcconfig file, you have to manually point arcanist to the right URL by running: arc diff --conduit-uri=https://phabricator.haskell.org Ryan S. ----- [1] http://git.haskell.org/hsc2hs.git

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Submitting a patch for hsc2hs
by Erik de Castro Lopo 04 Nov '16

04 Nov '16

HI all, How would I go about submitting a patch to hsc2hs? Patch below. Erik >From 446e43994e39c763e2fcc3a3accea3e61c3ce767 Mon Sep 17 00:00:00 2001 From: Erik de Castro Lopo <erikd(a)mega-nerd.com> Date: Fri, 4 Nov 2016 20:08:06 +1100 Subject: [PATCH] Fix type signature of main test function During C compiler feature testing, the `main` function was defined with a parameter list of `(int argc, char *argv [])` but these parameters were not used. This results in compiler warnings when the generated file is compiled with the `-Wextra` warning flag added to the `cc-options` of the cabal file. --- DirectCodegen.hs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/DirectCodegen.hs b/DirectCodegen.hs index 37564ee..2a88784 100644 --- a/DirectCodegen.hs +++ b/DirectCodegen.hs @@ -63,7 +63,7 @@ outputDirect config outName outDir outBase name toks = do outTemplateHeaderCProg (cTemplate config)++ concatMap outFlagHeaderCProg flags++ concatMap outHeaderCProg specials++ - "\nint main (int argc, char *argv [])\n{\n"++ + "\nint main (void)\n{\n"++ outHeaderHs flags (if needsH then Just outHName else Nothing) specials++ outHsLine (SourcePos name 0)++ concatMap outTokenHs toks++ -- 2.10.1 -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/

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Building with recent binutils require --no-pie
by Alan & Kim Zimmerman 04 Nov '16

04 Nov '16

Hi all For anyone building on Debian testing or similar and getting linker failures, there is currently a workaround in progress by Ben Gamari that can be used. It is based on first applying D2672, D2673, and D2674 and then configuring with ./configure \ CONF_CC_OPTS_STAGE2=-fno-PIE \ CONF_GCC_LINKER_OPTS_STAGE2=-no-pie \ CONF_LD_LINKER_OPTS_STAGE2=-no-pie \ CONF_CC_OPTS_STAGE0=-no-pie \ CONF_GCC_LINKER_OPTS_STAGE0=-no-pie \ CONF_LD_LINKER_OPTS_STAGE0=-no-pie \ CONF_HC_OPTS_STAGE0=-optl=-no-pie See https://gist.github.com/alanz/570eb6f1c0ae7e989f493f1b69904c28 for a more legible version. Regards Alan

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