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[network] #2: Socket related IO cannot be be interrupted on Windows
by network 26 Jan '09

26 Jan '09

#2: Socket related IO cannot be be interrupted on Windows ---------------------+------------------------------------------------------ Reporter: igloo | Owner: Type: defect | Status: new Priority: major | Milestone: Component: network | Version: Keywords: | ---------------------+------------------------------------------------------ Originally reported here: http://hackage.haskell.org/trac/ghc/ticket/2943 ---- While playing with socket communication, I noticed that socket IO cannot be interrupted or killed. The attached program simply hangs, irregardless whether is was complied using the -threaded flag or not. {{{ import Network import Control.Concurrent main = withSocketsDo $ do tid <- forkIO $ do s <- listenOn (PortNumber 1234) accept s return () threadDelay 2000000 killThread tid }}} -- Ticket URL: <http://trac.haskell.org/network/ticket/2> network <http://projects.haskell.org/network/> Networking-related facilities

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Tag cloud for hackage
by Don Stewart 25 Jan '09

25 Jan '09

http://donsbot.wordpress.com/2009/01/24/what-is-haskell-good-for/ The diversity, and focus, might be a surprise to some outside Haskell-land.

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Arch Haskell News: Jan 24 2009
by Don Stewart 24 Jan '09

24 Jan '09

http://archhaskell.wordpress.com/2009/01/24/arch-haskell-news-jan-24-2009/ A regular update of Haskell in Arch Linux Arch now has 864 Haskell packages in AUR. That’s an increase of 37 new packages in the last 13 days, or 2.8 new Haskell apps and libraries a day so far in January.

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cabal-1.6.0.1 won't build with ghc-6.6.1 in WinXP
by Alistair Bayley 23 Jan '09

23 Jan '09

I'm trying to build cabal-1.6.0.1 with ghc-6.6.1 on WinXP. "setup -v configure" fails with this output: Configuring Cabal-1.6.0.1... Flags chosen: base3=False, base4=False Dependency base <3: using base-2.1.1 Dependency filepath >=1 && <1.2: using filepath-1.0 Using Cabal-0 compiled by ghc-6.6 Using compiler: ghc-6.6.1 Using install prefix: C:\Program Files\Haskell Binaries installed in: C:\Program Files\Haskell\bin Libraries installed in: C:\Program Files\Haskell\Cabal-1.6.0.1\ghc-6.6.1 Private binaries installed in: C:\Program Files\Haskell\Cabal-1.6.0.1 Data files installed in: C:\Program Files\Haskell\Cabal-1.6.0.1 Documentation installed in: C:\Program Files\Haskell\doc\Cabal-1.6.0.1 No alex found Using ar found on system at: c:\ghc\ghc-6.6.1\bin\ar.exe No c2hs found No cpphs found No ffihugs found Using gcc version 3.4.2 found on system at: c:\ghc\ghc-6.6.1\gcc.exe Using ghc version 6.6.1 found on system at: c:\ghc\ghc-6.6.1\bin\ghc.exe Using ghc-pkg version 6.6.1 found on system at: c:\ghc\ghc-6.6.1\bin\ghc-pkg.exe No greencard found No haddock found No happy found No hmake found Using hsc2hs version 0.66 found on system at: c:\ghc\ghc-6.6.1\bin\hsc2hs.exe No hscolour found No hugs found No jhc found Using ld found on system at: c:\ghc\ghc-6.6.1\gcc-lib\ld.exe No nhc98 found No pkg-config found No ranlib found No strip found No tar found setup: fdGetMode: invalid argument (Invalid argument) Any clues as to what might be wrong? There are no buildinfo files produced, so I can't just ignore and proceed with setup build. Alistair

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1000 libraries
by Don Stewart 21 Jan '09

21 Jan '09

We've done it! http://hackage.haskell.org/cgi-bin/hackage-scripts/stats 274 users have uploaded 3161 versions of 1000 packages. Thanks everyone who has written a library or tool or app and released it, for making hackage and cabal a success! This has gone further, perhaps more than anything else, towards making it possible to use Haskell in industry. The lucky 1000th package is: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/threadPool-0.1 threadPool: Runs other programs in the manner of a thread pool Takes a single, optional argument which is the number of threads (the default is three). Give it the commands to run, one per line, through standard input. Author Brian Jaress Now, onto 10k libraries! -- Don

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Main-Is not creating executable
by Alistair Bayley 21 Jan '09

21 Jan '09

I have this in Takusen.cabal: Executable miniunit_tests Main-Is: Test/MiniUnit/Main.hs Build-Depends: base, mtl Extensions: CPP CPP-Options: "-DNEW_EXCEPTION" (as well as the Library section). When it builds, the modules compile fine, but then I get: Warning: output was redirected with -o, but no output will be generated because there is no Main module. The ghc command (from setup -v build): Building executable: miniunit_tests... Creating dist\build\miniunit_tests (and its parents) Creating dist\build\miniunit_tests\miniunit_tests-tmp (and its parents) c:\ghc\ghc-6.10.1\bin\ghc.exe -o dist\build\miniunit_tests\miniunit_tests.exe -- make -hide-all-packages -no-user-package-conf -i -idist\build\miniunit_tests\min iunit_tests-tmp -i. -idist\build\autogen -Idist\build\autogen -Idist\build\miniu nit_tests\miniunit_tests-tmp -optP-DNEW_EXCEPTION -optP-include -optPdist\build\ autogen\cabal_macros.h -odir dist\build\miniunit_tests\miniunit_tests-tmp -hidir dist\build\miniunit_tests\miniunit_tests-tmp -stubdir dist\build\miniunit_tests \miniunit_tests-tmp -package QuickCheck-1.2.0.0 -package Takusen-0.8.4 -package base-4.0.0.0 -package mtl-1.1.0.2 -package old-time-1.0.0.1 -package time-1.1.2. 2 -O -XCPP .\Test/MiniUnit/Main.hs I don't see ghc flag -main-is in here. What do I need to do to get it to build the executable? Also, is there a way to get it to just build miniunit_tests.exe i.e. without rebuilding the library and another executable target? Alistair

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[network] #3: Cannot call connect with a socket that is already bound.
by network 20 Jan '09

20 Jan '09

#3: Cannot call connect with a socket that is already bound. ---------------------+------------------------------------------------------ Reporter: igloo | Owner: Type: defect | Status: new Priority: major | Milestone: Component: network | Version: Keywords: | ---------------------+------------------------------------------------------ Originally reported here: http://hackage.haskell.org/trac/ghc/ticket/2784 ---- {{{ > import Network.Socket > sock <- socket AF_INET Datagram 0 Loading package parsec-2.1.0.1 ... linking ... done. Loading package network-2.2.0.1 ... linking ... done. > bindSocket sock (SockAddrInet aNY_PORT iNADDR_ANY) > connect sock undefined *** Exception: user error (connect: can't peform connect on socket in status Bound) }}} Network.Socket.connect checks the !SocketStatus of the socket: {{{ if currentStatus /= NotConnected }}} From [http://www.opengroup.org/onlinepubs/000095399/functions/connect.html The Open Group Base Specifications Issue 6]: "If the socket has not already been bound to a local address, connect() shall bind it to an address which, unless the socket's address family is AF_UNIX, is an unused local address." -- Ticket URL: <http://trac.haskell.org/network/ticket/3> network <http://projects.haskell.org/network/> Networking-related facilities

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Participation in Cabal / Hackage development
by Duncan Coutts 20 Jan '09

20 Jan '09

All, I just mentioned ideas for Cabal 2 but I should also like to talk about how we can go about increasing participation in the development effort. We currently have nearly 200 open tickets which include many important bugs and no shortage of good ideas for useful new features. Our limiting factor is developer time. Most of us use the Cabal / Hackage system in one way or another. Most of us are familiar with its annoyances and limitations. Unfortunately the number of people helping out has dropped rather in the past year or so. Perhaps we should run a little poll like the darcs hackers did to find out what we could do to increase participation so we can get on with building the tools that we all want, but a bit more quickly. Duncan

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Re: [Haskell-cafe] Cabal dependencies
by Duncan Coutts 20 Jan '09

20 Jan '09

On Thu, 2009-01-15 at 18:38 -0500, Stephen Hicks wrote: > Hi, > > I'm having some difficulty specifying dependencies in my .cabal file > for a package I'm looking to upload to hackage soon. The difficulty > is as follows. I basically want to specify > parsec (>= 2.1 && < 3.0.0) || (> 3.0.0 && < 4) When we first introduced this kind of version range syntax we were unsure if it was too general or not. We want to be able to translate into other systems and they're typically more restrictive. Internally we can easily represent the above expression as it uses arbitrary unions and intersections. However the external parser still only allows two clauses (I think it's two). Personally I'm all for lifting that restriction. Yes it makes it a bit harder for translating into some systems but I don't see that as a real issue. If the package really does require the more complex version range then forcing the package author to lie by using a less expressive syntax does not help. We can still make the same choice at the point when we translate into native packages. Also, as it happens there is a way of getting around the restriction anyway, which makes the restriction effectively pointless. That is by listing the same dependency more than once. All the version constraints must be satisfied so you can write: build-depends: parsec >= 2.1 && < 4, parsec < 3.0.0 || > 3.0.0 (have I got that right?) So I'd be interested to get feedback on lifting the restriction and the impact that might have on translation into native packages. > The problem is that 3.0.0 as it exists on hackage is missing a > constructor that I need (namely, Postfix, in the compatibility > module). The bug was fixed and will presumably work fine if a newer > version of parsec is ever uploaded to hackage, and my package works > fine with older parsecs as well - I just want to exclude this one > version. How can I go about doing that? Try the above. > A secondary question is this - I can actually compile with version > 3.0.0 by just not using this constructor, although it does reduce the > package's functionality. I've seen flags in various .cabal files, and > presumably I could invent a flag to make it work with 3.0.0, but I'm > confused about how these flags are set. Yes, if you need compatibility with older versions of Cabal then you'd need to use a flag. If you're prepared to require Cabal-1.6 or later then you can use the cpp macro: #if MIN_VERSION_parsec(3,0,0) though of course that only gives you >= 3.0.0, you'd need more tricky combinations to get == 3.0.0, perhaps by assuming >= 3.0.1 is ok. For older Cabal versions the main option is a flag, like so: flag parsec3 ... if flag(parsec3) build-depends: parsec == 3.0.0 cpp-options: -DUSING_BAD_PARSEC else build-depends: parsec > 3.0.0 || < 3.0.0 > Specifically, cabal-install has never asked me anything about flags, > so what's the point? Or does it automatically set whichever flags > satisfy the dependencies? It tries to work out what flags to set automatically (based on the platform, the available packages and flag defaults in each package). You can override them from the command line if you want to or need to. Duncan

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Copyright for readline library
by Kari Pahula 20 Jan '09

20 Jan '09

I would use readline instead of editline to build ghc6 on Debian, but the readline library package in Hackage has a problem. I downloaded version 1.0.1.0 from http://hackage.haskell.org/cgi-bin/hackage-scripts/package/readline and found this in System/Console/Readline.hsc: -- Module : System.Console.Readline -- Copyright : (c) unknown I'm afraid I can't use it as it is. Is there anything I could do to help to find the correct attribution for this file?

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