How to specify path to `llvm` for `ghc` and `cabal`? - haskell

I'm trying to add the new llvm path to cabal to build with -fllvm option because I receive the error that it can't see the newer version:
<no location info>: error:
Warning: Couldn't figure out LLVM version!
Make sure you have installed LLVM 5.0
I have LLVM 5 installed under this path: /usr/local/Cellar/llvm#5/5.0.2/bin/. I need to somehow tell this to cabal but I can't find where to do this. In stack there is settings file under the installed ghc, but what is the wright way to do this for cabal?

I would start with
export PATH=/usr/local/Cellar/llvm#5/5.0.2/bin/:$PATH
cabal install
and see if that works.
I don't see any mention of options to set the LLVM path in the GHC user guide or the --with-PROG section of cabal configure --help. It certainly seems like a reasonable flag to add to cabal. The GHC guide only mentions finding it on PATH.

Related

Cabal can't find foreign libraries

Recently I was trying to install llvm-general-3.5.1.0 package.. for about a week. Basically I am getting this error: link. My situation is identical. Windows 10, ghc 7.10.2, cabal 1.22.4.0. I installed llvm 3.5.2 from sources with cmake and everything went fine. In llvm/lib directory I have *.lib files (eg. LLVMAnalysis.lib).
But somehow cabal can't see those libraries and gives this frustrating error:
Configuring llvm-general-3.5.1.0...
setup.exe: Missing dependencies on foreign libraries:
* Missing C libraries: LLVMLTO, LLVMObjCARCOpts, LLVMLinker, LLVMipo,
LLVMVectorize, LLVMBitWriter, LLVMCppBackendCodeGen, LLVMCppBackendInfo,
LLVMTableGen, LLVMDebugInfo, LLVMOption, LLVMX86Disassembler,
LLVMX86AsmParser, LLVMX86CodeGen, LLVMSelectionDAG, LLVMAsmPrinter,
LLVMX86Desc, LLVMX86Info, LLVMX86AsmPrinter, LLVMX86Utils, LLVMJIT,
LLVMIRReader, LLVMAsmParser, LLVMLineEditor, LLVMMCAnalysis,
LLVMMCDisassembler, LLVMInstrumentation, LLVMInterpreter, LLVMCodeGen,
LLVMScalarOpts, LLVMInstCombine, LLVMTransformUtils, LLVMipa, LLVMAnalysis,
LLVMProfileData, LLVMMCJIT, LLVMTarget, LLVMRuntimeDyld, LLVMObject,
LLVMMCParser, LLVMBitReader, LLVMExecutionEngine, LLVMMC, LLVMCore,
LLVMSupport
This problem can usually be solved by installing the system packages that
provide these libraries (you may need the "-dev" versions). If the libraries
are already installed but in a non-standard location then you can use the
flags --extra-include-dirs= and --extra-lib-dirs= to specify where they are.
I really want to use this package on my Windows, but nothing seems to work (I tried everything like --extra-lib-dirs and compiled also with MinGW and VS - the same problem).
I can't accept the fact that it won't install. I mean, there must be some way to fix Setup.hs from this cabal package or something. Does anyone have an idea what can be wrong with cabal in this case and how can I try to workaround this? I don't know how exactly cabal works, maybe someone with this knowledge will have an idea? Or maybe there is a way to do this without cabal?
Ok, i've managed to build it and, i think, found the root of the issue.
First, steps to build:
Get the MinGW. My installation of MinGW has gcc 4.8.
Get 32-bit MinGHC.
Compile LLVM 3.5 with MinGW's gcc and install it somewhere.
Copy contents of MinGW installation directory into MinGHC Install
Dir\ghc-7.10.2\mingw, replacing conflict files.
In the command line set your PATH so it has haskell toolset from
MinGHC (i recommend using switch .bat scripts) and llvm-config.exe.
Get the llvm-general package source either using cabal fetch or
downloading via browser from hackage.
Replace cc-options: -std=c++11 line of llvm-general.cabal with
cc-options: -std=gnu++11.
Finally, cabal configure and cabal build should work.
I have been changing my build environment many times, so if this doesn't work for you let me know, i probably forgot something.
Now let's go into details.
What we thought is a bug of cabal is not, actually. The problem is that both stack and MinGHC (and Haskell Platform, i guess) use quite old gcc - 4.6. This gcc has even two defects:
It doesn't support -std=c++11 and LLVM 3.5 can't be built using it.
As a consequence, this gcc can't be used by ghc when compiling
llvm-general, because it can't parse LLVM headers properly.
Even if it could, its linker can't link against LLVM libs compiled by
MinGW using gcc 4.8. This is why cabal was telling you it
couldn't find LLVM libs. I've hacked Setup.hs so that it wouldn't
look for these libs, but pass -lLLVMSomething to linker via -pgml
ghc option. This lead to clear error message:
ld.exe: ignoring libLLVMSupport.a ...
ld.exe: can't find -lLLVMSupport
So, the cabal was actually finding these libs, but was dropping them because they couldn't be linked to.
Ideally, the solution would be to update mingw distribution used by stack/MinGHC. But as a workaround you can just replace old gcc with new one.
Finally, -std=gnu++11 is used because current MinGW release is affected by this bug, which prevents compilation of c++ bits of the package. Whew, that was a long way.

hackage-server fails to build - are there specific ghc/cabal version requirements?

I am trying to build and run a copy of the Hackage server https://github.com/haskell/hackage-server. I followed the instructions here https://github.com/haskell/hackage-server/wiki and also the instructions in the readme. Whichever I try, when trying to build with ghc 7.8.4 and cabal 1.22 I receive the following error:
Preprocessing executable 'hackage-server' for hackage-server-0.5.0...
Main.hs:40:8:
Could not find module ‘Network.URI’
It is a member of the hidden package ‘network-uri-2.6.0.1’.
Perhaps you need to add ‘network-uri’ to the build-depends in your .cabal file.
It is a member of the hidden package ‘network-2.4.2.3’.
Perhaps you need to add ‘network’ to the build-depends in your .cabal file.
I have also tried using the latest Haskell Platform, and I get the same failure message.
I'm trying to work out if this is a bug in the current master branch of hackage-server or if it is something to do with the way I installed ghc or cabal.
EDIT: I've tried again with the Ubuntu 14.04 repo haskell-platform (ghc 7.6.3, cabal 1.16) and the same error happens.
network-uri was split from network a while ago, but it looks like Hackage hasn't been updated with that change.
As a workaround, open hackage-server.cabal and add these lines to build-dependencies:
network >= 2.6,
network-uri >= 2.6
That should get it working again.

Installing SDL on Windows for Haskell (GHC)

Background:
I've been using the gloss library for some simple diagram work. But when it came time for something more interactive, I found I wanted a more powerful library. After doing some research, I decided that I liked the features of the SDL library and wanted to try to install the Haskell bindings for it. I have to this point been unsuccessful.
Part 1:
How do I install and configure the SDL binaries so that they can be used by the Haskell bindings?
Part 2:
Which one of the numerous and ill documented SDL packages on Hackage it the current preferred binding in the community? How do I get that package to install correctly?
Part 3: (Optional)
If SDL is not a good fit for haskell development what is the preferred alternative?
I am going to answer your question for SDL2 (should also work for SDL1 with some modifications).
Install pkg-config for Windows
(How to install pkg config in windows?)
This tool is very important. It is used by various Cabal packages to search for libraries and contains directions for linking and compiling.
Download the SDL development libraries for Windows/MinGW:
http://libsdl.org/release/SDL2-devel-2.0.3-mingw.tar.gz
If you have installed the 32-bit version of the Haskell platform, extract the folder i686-w64-mingw32
For 64-bit versions extract x86_64-w64-mingw32
You will get following layout:
include
share
bin
lib
"Register" the library with pkg-config.
Either copy lib/pkgconfig/sdl2.pc into the folder of your pkg-config.exe or modify/create the PKG_CONFIG_PATH accordingly. Check that you set up everything correctly:
C:\pkg-config --list-all | grep sdl2
sdl2 sdl2 - Simple DirectMedia Layer is a cross-platform multimedia
library designed to provide low level access to audio, keyboard,
mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer.
Add the bin folder to your PATH environment variable.
Install the sdl2 package via the Cabal installer and tell Cabal where to find your libraries.
Example:
cabal install sdl2 --extra-include-dirs=C:\lib\sdl2\include --extra-lib-dirs=C:\lib\sdl2\lib\
To test my installation, I have written a small example:
https://github.com/ftl2014/haskell-stuff/blob/master/sdl/
Caveat emptor:
If Cabal complains about a "missing" library, it might be the case that library was actually found but it is incompatible (e.g. using a 32-bit instead of a 64-bit version) or corrupt. The same is true for header files.
For some reason, Cabal complained about not finding SDL.h, and I had to use the headers in the root include folder of the archive (but maybe I was just drinking too much Kool-aid).
I wasn't able to get it to install on my system. Here's what I tried. Strangely, I was able to get configure find the header files but not the actual binary.
Let's try it. I have installed the new 2014 Haskell Platform.
cabal install sdl
Configuring SDL-0.6.5...
setup.exe: The package has a './configure' script. This requires a Unix
compatibility toolchain such as MinGW+MSYS or Cygwin.
Failed to install SDL-0.6.5
GHC in the Haskell Platform comes with MinGW, so we probably need to install MSYS. The MSYS page says to install minggw get, which says to install
An automated GUI installer assistant called mingw-get-setup.exe is the preferred method for first time installation. This will guide you through the setup of the mingw-get installer proper; you will then use this to perform further package installations, and to manage your installation.
Running the installer with the default options gives us the following screen:
We already have mingw from installing the Haskell platform, so we'll click on only the last item in the list, msys-base, and select "Mark for Installation". Then, in the "Installation" menu in the top left, select "Apply Changes". This asks if it is ok to proceed, and we select "Apply"
This installer didn't put msys-base in the path, we can add it to the path, and try installing sdl again
set PATH=C:\MinGW\msys\1.0\bin\;%PATH%
cabal install sdl
Configuring SDL-0.6.5...
configure: WARNING: unrecognized options: --with-compiler, --with-gcc
checking for sdl-config... no
checking for sdl11-config... no
configure: error: *** SDL not found! Get SDL from www.libsdl.org.
If you already installed it, check it's in the path. If problem remains,
please send a mail to the address that appears in ./configure --version
indicating your platform, the version of configure script and the problem.
Failed to install SDL-0.6.5
We need to download and install libsdl. I went to the libsdl download page and downloaded the Win32 development libraries, SDL-devel-1.2.15-mingw32.tar.gz. I extracted this archive (7-zip can extract both tar archives and gzip compressed files). For convenience, I moved the SDL-1.2.15 directory to c:. We'll add this to the path, as suggested by the previous error, and try again
set PATH=C:\SDL-1.2.15\bin\;%PATH%
cabal install sdl
* Missing (or bad) header file: SDL/SDL.h
* Missing C library: SDL
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.
If the header file does exist, it may contain errors that are caught by the C
compiler at the preprocessing stage. In this case you can re-run configure
with the verbosity flag -v3 to see the error messages.
We can make part of this error go away by adding the suggested --extra-include-dirs flag, but still get the following error
cabal install sdl --extra-include-dirs=c:\SDL-1.2.15\include
* Missing C library: SDL
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.
Adding the --extra-lib-dirs flag with c:\SDL-1.2.15\bin or C:\SDL-1.2.15\lib or c:\SDL-1.2.15 failed to fix this problem.

haskell snap exitfailure 1

I am new to Haskell, and wanted to play around with snap framework. Unfortunately I just cant get the thing to compile. I've tried (all I know too), updating cabal and running sudo ghc-pkg recache but I still get the following when I run cabal install snap. Please help.
12 warnings and 1 error generated.
Failed to install binary-0.7.1.0
cabal: Error: some packages failed to install:
SHA-1.6.4 depends on binary-0.7.1.0 which faile
d to install.
binary-0.7.1.0 failed during the building phase
. The exception was:
ExitFailure 1
pwstore-fast-2.4.1 depends on binary-0.7.1.0 wh
ich failed to install.
snap-0.13.2.2 depends on binary-0.7.1.0 which f
ailed to install.
Solution:
I first install the 'real' gcc via homebrew like so:
brew update
brew install gcc47
This took a while to install (as in over an hour). Once it was done I updated the GHC settings to use the copy of gcc installed by homebrew.
GHC settings are located either here :
/Library/Frameworks/GHC.framework/Versions/Current/usr/lib/ghc-7.6.3/settings
or here if you installed ghc with homebrew (I did not).
/usr/local/Cellar/ghc/7.6.3/lib/ghc-7.6.3/settings
Update the line
("C compiler command", "/usr/bin/gcc")
to
("C compiler command", "/usr/local/Cellar/gcc47/4.7.3/bin/gcc-4.7")
Then just run
cabal update && cabal install snap
and all should be well. :)
Your problem is that the binary package has some C preprocessor constructs that are not strictly valid.
After looking around a bit, I found a similar problem somebody had when installing the Haskell platform. It seems the core issue is that the Clang C preprocessor is stricter than the GCC one most Haskellers use. I'm assuming that this is your problem: you're using Clang rather than GCC. If you're on OS X, this is the default choice.
The easiest solution seems to be to switch to using GCC for the preprocessing. Note that on OS X, /usr/bin/gcc actually points to Clang! You will need to point GHC to an actual install of GCC.
You can do this by editing GHC's configuration file. On my system it's found at
/usr/local/lib/ghc-7.6.3/settings
Yours is probably somewhere similar, although I'm on Linux rather than OS X. In the file, change
("C compiler command", "/usr/bin/gcc")
to point to an actual copy of gcc rather than Clang and try installing again.
In the long run, this feels like a bug with the package and probably needs to be addressed, although I don't really know enough about the issue or constraints package authors have to be sure.

ghc can't find my cabal installed packages

I've installed ghc 6.12.3, and then the Haskell Platform. I'm trying to compile a test program:
$ ghc test.hs
test.hs:3:0:
Failed to load interface for `Bindings':
Use -v to see a list of the files searched for.
so, naturally, I do
cabal install Bindings
Which works fine, and places the package in ~/.cabal/lib/bindings-0.1.2 The problem is, that when I go to compile again with ghc, it still doesn't find the package I've installed with cabal.
compiling in verbose mode gives:
ghc -v test.hs
Using binary package database: /home/ludflu/ghc/lib/ghc-6.12.3/package.conf.d/package.cache
Using binary package database: /home/ludflu/.ghc/x86_64-linux 6.12.3/package.conf.d/package.cache
As suggested by another stackoverflow user, I tried:
ghc-pkg describe rts > rts.pkg
vi rts.pkg # add the /home/ludflu/.cabal/lib to `library-dirs` field
ghc-pkg update rts.pkg
But to no avail. How to I add the .cabal to the list of package directories to search?
Thank you!
You can check which packages are installed with ghc-pkg list. It may be that you need to either specify the packages to ghc with -package <pkgname> or I believe adding --make to will trigger a chasing down of dependencies, including packages.
Edit: the bindings package is obsolete indeed, see the hackage page. This isn't a package management problem, the only module available is Bindings.Deprecated, which you are perfectly able to load, even though it is an empty module. I believe the relevant parts have been broken out into bindings-<module>, so if you want the bindings functionality you should look to those packages.
http://www.haskell.org/haskellwiki/Cabal-install
One thing to be especially aware of, is that the packages are installed locally by default by cabal, whereas the commands
runhaskell Setup configure
runhaskell Setup build
runhaskell Setup install
install globally by default. If you install a package globally, the local packages are ignored. The default for cabal-install can be modified by editing the configuration file.
I was getting the same error with the runhaskell command. I used the cabal in the directory that had the .cabal file and was able to resolve the error.

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