- Glasgow-haskell-users

Edentv build
by Aswad, Mustafa 31 Dec '10

31 Dec '10

Hi Mesha; I try to build the latest version from edentv, but I have problem to build the depends packages. I am stick to build "cairo", it gives my the following error Preprocessing library cairo-0.12.0... Building cairo-0.12.0... Graphics/Rendering/Cairo.hs:8:0: error: cairo-version.h: No such file or directory It is required by GTK packages. Can you till where I can find the right version that can build with ghc-6.12.3 or to install this package? I have tried the one which in http://hackage.haskell.org/packages/archive/cairo/0.12.0/ but it does not work. cheers -- Heriot-Watt University is a Scottish charity registered under charity number SC000278.

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Re: [darcs-users] How to develop on a (GHC) branch with darcs
by Iavor Diatchki 22 Dec '10

22 Dec '10

Hello, Thanks for all your responses (and the --skip-conflicts tip)! I use git for a lot of my development, so I was hoping that I was just experiencing "culture shock" and simply doing things with the wrong mind-set. Given the responses though, it sounds like this is a well known problem with darcs with no obvious solution. For me, switching GHC to git would certainly be a win. In terms of the future of darcs, while better tools for managing rebasing would certainly be useful, I am not confident that any solution based on mutation (i.e., "rewriting history" by rebasing/ amend-recoding) would work well in a distributed environment due to the difficulty of sharing these changes---it seems to require some sort of "higher order" version control where you have to keep track of the changes to the changes :-) In the context of git, I only brought up "rebasing" because it seemed like the closest concept to what I was doing with darcs. If GHC was to switch to git, I think that we should certainly use git's ordinary merge model to keep track of history. -Iavor PS for VCS folks: I think that an interesting idea of combining darcs and git would be to use git's graph-based history model, but to annotate the edges on the graph with semantic patches ala darcs. This would make it possible to write smarter auto-merge strategies for git. On Tue, Dec 7, 2010 at 7:16 AM, Stephen J. Turnbull <stephen(a)xemacs.org> wrote: > Ganesh Sittampalam writes: > > > I think there are three things that can help with this problem: > > > > 1) a darcs rebase command. This will give you a nice way to manage the > > workflow already discussed, and you won't have to squish everything > > through into a mega-patch. You'll still have to periodically abandon one > > branch for another though (but I think that's also the case with git > > rebase). > > I'm not sure what you mean by "abandon". > > In a git rebase, you pretty much have to forget the original branch > immediately (everywhere in the world!), or there will be great fun for > all concerned. You really really do not want to merge an original > branch with its rebased descendant in git.[1] Unfortunately, unless > the rebased branch gets dibs on the branch's name, it's all too easy > to perform such a merge inadvertantly (eg, git pull will do it). So > in that sense a git rebase means immediately abandoning the old branch, > and all the commit history of the old branch. (The details of the > history are copied into the rebased commits, but they do not have the > same identity as the originals, so merge conflicts are guaranteed.) > > > I also have some hope, though this is more speculative, of offering > > a clean way of tracking the relationship between the old branch and > > the new branch so that any stray patches against the old branch can > > be cleanly rebased to the new branch later on. > > As explained above, DAG-based VCSes like git can't do this cleanly > (that is one way of expressing the reason why rebase is severely > deprecated in some circles), and I don't think git will be able to do > so in the near future. OTOH, if Darcs gets rebase but can't handle > this, I'd have to count that as a net minus. Recombinant patching is > really what Darcs is all about IMO. > > In practice, git rebase needs to be kept private to a single user, and > is impractical even if private, if the user has propagated the branch > to other local repositories. Because git branching is so lightweight, > nobody really sees this as a big problem; throwaway branches are used > all the time as interim steps in many operations (eg, git stash). > Darcs branches, on the other hand, are much more heavyweight (modulo > the work you propose on colocated branches, but that's farther away > than rebase is). > > IMHO YMMV. But I strongly recommend you think carefully about this. > Analogies to git rebase are a trap here. It's implemented differently > and used to solve different problems from the way rebase is proposed > for use in Darcs. > > > Footnotes: > [1] There may be better ways to deal with this than garbaging the > original commits, but so far nobody really needs it. > >

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Beware: Bad I/O performance on Windows without -threaded
by Simon Marlow 21 Dec '10

21 Dec '10

I just noticed that I/O performane on Windows without -threaded is pretty terrible. The following program: main = getConetnts >>= putStr tested with a 1MB file: $ rm cat.exe; ghc-7.0.1 --make -rtsopts cat.hs $ ./cat <1M >/dev/null +RTS -s <snip> Total time 0.28s ( 0.49s elapsed) <snip> But if we add -threaded: $ rm cat.exe; ghc-7.0.1 --make -rtsopts cat.hs -threaded $ ./cat <1M >/dev/null +RTS -s <snip> Total time 0.05s ( 0.07s elapsed) <snip> Several times better. I just made a tweak in my working tree to increase the I/O buffer sizes, and this helps quite a lot: $ rm cat.exe; ../ghc-testing/inplace/bin/ghc-stage2.exe --make -rtsopts cat.hs $ ./cat <1M >/dev/null +RTS -s <snip> Total time 0.06s ( 0.05s elapsed) <snip> $ rm cat.exe; ../ghc-testing/inplace/bin/ghc-stage2.exe --make -rtsopts cat.hs -threaded $ ./cat <1M >/dev/null +RTS -s <snip> Total time 0.05s ( 0.05s elapsed) <snip> Why is this? I'm not entirely sure, but I suspect it is the implementation of asynchronous I/O in the RTS that is only used on Windows without -threaded (rts/win32/AsyncIO.c etc.). Every I/O operation in the non-threaded RTS on Windows involves a couple of OS-thread switches. I'll get the buffer size fixes into 7.0.2. Cheers, Simon

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GIO.012.0 installation
by Aswad, Mustafa 21 Dec '10

21 Dec '10

Hi dear; I am try to build Gio package using cabal version cabal-install version 0.8.2 and Ghc version version 6.12.3. Bu I got such error which I can not solve it setup: The pkg-config package gio-2.0 version >=2.16.4 is required but it could not be found. Could any of you till me how come this problem. thanks -- Heriot-Watt University is a Scottish charity registered under charity number SC000278.

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client builder issue.
by Karel Gardas 17 Dec '10

17 Dec '10

Hello, I've attempted to update my builder client to the today's source code and compiled it by GHC 7.0.1 (I've hacked cabal files' versions in order to do so). When running against GHC builder server with --do-build option I've got following failure: Running "testing" builder-client-v2: fd:11: hGetLine: invalid argument (Illegal byte sequence) [2010-12-17 12:14:05] [kgardas-opensolaris-x86-head] Sending: "UPLOAD 79 1" builder-client-v2: SSLIOError I guess due to it, my testing fails with: =====> print021(ghci) 286 of 2675 [0, 1, 0] cd ./ghci.debugger/scripts && HC='/buildbot/ghc-head-builder/builder/tempbuild/build/bindisttest/install dir/bin/ghc' HC_OPTS='-dcore-lint -dcmm-lint -dno-debug-output -no-user-package-conf -rtsopts ' '/buildbot/ghc-head-builder/builder/tempbuild/build/bindisttest/install dir/bin/ghc' --interactive -v0 -ignore-dot-ghci -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-conf -rtsopts -ignore-dot-ghci <print021.script >print021.run.stdout 2>print021.run.stderr Actual stdout output differs from expected: --- ./ghci.debugger/scripts/print021.stdout.normalised Fri Dec 17 14:14:05 2010 +++ ./ghci.debugger/scripts/print021.run.stdout.normalised Fri Dec 17 14:14:05 2010 @@ -1,2 +1,2 @@ test = (_t1::[T]) Traceback (most recent call last): File "../../driver/runtests.py", line 238, in ? oneTest() File "/buildbot/ghc-head-builder/builder/tempbuild/build/testsuite/driver/testlib.py", line 479, in <lambda> allTests += [lambda : runTest(myTestOpts, name, setup, func, args)] File "/buildbot/ghc-head-builder/builder/tempbuild/build/testsuite/driver/testlib.py", line 469, in runTest test_common_work (name, opts, func, args) File "/buildbot/ghc-head-builder/builder/tempbuild/build/testsuite/driver/testlib.py", line 545, in test_common_work do_test (name, way, func, args) File "/buildbot/ghc-head-builder/builder/tempbuild/build/testsuite/driver/testlib.py", line 666, in do_test framework_fail(name, way, 'do_test exception') File "/buildbot/ghc-head-builder/builder/tempbuild/build/testsuite/driver/testlib.py", line 679, in framework_fail print '*** framework failure for', full_name, reason, ':' IOError: [Errno 32] Broken pipe gmake[2]: *** [test] Error 1 gmake[1]: *** [fast] Broken Pipe gmake: *** [test] Broken Pipe Or is it vice versa? See http://darcs.haskell.org/ghcBuilder/builders/kgardas-opensolaris-x86-head/7… is this a known issue or shall I do something about it? Thanks, Karel

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Newtype deriving mixing up types
by Emil Axelsson 17 Dec '10

17 Dec '10

Hello! I attach a program which I suspect demonstrates a bug in GHC. The important lines are: showType :: forall a . Expr a -> String showType (Lit _) = show (typeOf (undefined :: a)) test1 = showType (mk :: Expr BOOL) -- Prints "Bool" (wrong?) test2 = showType (Lit mk :: Expr BOOL) -- Prints "Main.BOOL" (correct) test1 and test2 give different results, even though showType shouldn't be able to tell them apart. It seems that the Typeable context packed with the Lit constructor is wrong in test2. I had to use two extra classes and newtype deriving to trigger this behavior. Note that if I change deriving instance B BOOL to instance B BOOL the result is correct. Tested with both 6.12.3 and 7.0.1. Should I report this as a bug? Thanks! / Emil

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Printing of asynchronous exceptions to stderr
by Mitar 16 Dec '10

16 Dec '10

Hi! I have been spend some time to debug this in my program. ;-) Why is ThreadKilled not displayed by RTS when send to thread (and unhandled), but any other exception is? For example, I am using custom exceptions to signal different kinds of thread killing. Based on those my threads cleanup in different ways. But after they cleanup they keep "running". Not really running as their computations were interrupted. But simply hanging there. And if then new custom exception arrives it is not handled anymore (as it is after my normal exception handlers already cleaned everything) and it is printed to stderr. Now I added "`finally` throwIO ThreadKilled" at the end of my cleanup computations to really kill the thread. So that possible later exceptions are not delivered anymore. Why it is not so that after all computations in a thread finish, thread is not killed/disposed of? Because it can be reused by some other computation? But then my exceptions could be delivered to wrong (new) thread while they were meant for old one? Mitar

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build issue: * Missing header file: HsBase.h
by Karel Gardas 16 Dec '10

16 Dec '10

Hello, I'm trying to recover my opensolaris builder machine after disk crash, but after reinstall I'm not able to build any GHC there. I'm trying head and now also 6.12.3 as a reference (as I'm able to build it on my workstation with the same OS). The problem I see here is when I invoke `gmake' then the process continues up to configuration of base library which fails with: checking value of ETIMEDOUT... 145 checking value of ETOOMANYREFS... 144 checking value of ETXTBSY... 26 checking value of EUSERS... 94 checking value of EWOULDBLOCK... 11 checking value of EXDEV... 18 checking value of ENOCIGAR... -1 checking value of SIGINT... 2 checking value of O_BINARY... 0 checking for library containing iconv... none required configure: creating ./config.status config.status: creating base.buildinfo config.status: creating include/HsBaseConfig.h configure: WARNING: unrecognized options: --with-compiler ghc-cabal: Missing dependency on a foreign library: * Missing header file: HsBase.h This problem can usually be solved by installing the system package that provides this library (you may need the "-dev" version). If the library is already installed but in a non-standard location then you can use the flags --extra-include-dirs= and --extra-lib-dirs= to specify where it is. gmake[1]: *** [libraries/base/dist-install/package-data.mk] Error 1 gmake: *** [all] Error 2 The problem is HsBase.h is where it is on my reference build tree on workstation: -bash-4.0$ find . -name 'HsBase.h' ./libraries/base/include/HsBase.h -bash-4.0$ I suppose some external library might be missing, but here the error is quite misleading and I cannot find which one might be the culprit of this error. Do you have any idea what to install in order to proceed? Thanks! Karel

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Re: [Haskell] Terms of Service for Haskell community server
by Christian Höner zu Siederdissen 15 Dec '10

15 Dec '10

Hi, you probably mean generating an ssh key-pair. This is a one-step operation. Is Yarrow a weapon or a crypto package? Otherwise I would suggest putting Yarrow onto your personal webpage / university system and asking for a link. Gruss, Christian PS: I have just skimmed the TOS, but apart from the crypto (weapon ;-) stuff, it seems to be mostly standard US legalize. Of course, I am no lawyer. * Frank Rosemeier <frank(a)rosemeier.info> [15.12.2010 23:57]: > > Dear Haskellers, > > as some of you may have noticed, the Yarrow home page has to be > moved because of the migration of the Haskell.org server. > It has been recommended to me by Ian Lynagh to transfer the files to > the new community server. > To do so I need first to request for an account there. > > This includes producing an ssh certificate. I will try to solve this > problem. (May be there will be questions in the future.) > > The more severe problem is related to the Terms of Service which I > have to accept with the account request. > It contains lots of legal stuff which I do not understand including > regulations for US export controls. > Of course I am neither able nor willing to send reports concerning > Yarrow to the US government! > > Are there some experts or tutors who want to help me to understand > the Terms of Service especially the export controls? > May be these regulations do not apply in my case, because I am > living in Germany? > (I have expected lots of work to be done with respect to the migration, > but I did not imagine to be involved in legal affairs which I do not > understand.) > > Thank you very much for your patience. > > > Kind regards > > Frank Rosemeier > > _______________________________________________ > Haskell mailing list > Haskell(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell

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Oversized libraries
by Audrius Šaikūnas 14 Dec '10

14 Dec '10

Hello, I've noticed that libraries that are compiled even with -dynamic are really huge: libHScairo-0.12.0-ghc6.12.1.so - 1.4 M libHSgio-0.12.0-ghc6.12.1.so - 1.6 M libHSgtk-0.12.0-ghc6.12.1.so - 14 M (ldd confirms that these libraries are really linked dynamically with the rest of the world) just to name a few. All of them are striped with "strip -s". At this point *bindings* to C libraries are larger that the libraries themselves, which I find unacceptable. So I decided to dig a bit deeper and when examining cairo-0.12.0 I found that Types.o object file consumes 1.5 MB. So I "cleaned" up Types.hs and tried to compile it separately from the rest of the library: % ghc -c Types.hs && ls -lh | grep Types.o -rw-r--r-- 1 angel angel 69K 2010-12-14 18:24 Types.o % rm Types.o % ghc -c Types.hs -O && ls -lh | grep Types.o -rw-r--r-- 1 angel angel 1.1M 2010-12-14 18:25 Types.o So adding -O when compiling Types.hs makes the size of object file jump from 69K to 1.1M. Just think about it - the file contains *two* *enums* and nothing more. And yet it twice as large as a full-blown application like gedit. So I would like to ask you whether such behavior is known and should such this be considered as a bug? I've attached the testcase. It also can be found here: http://hpaste.org/42331/something Btw, I'm using GHC 6.12.1, x86_64. Best regards, Audrius

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