Re: Haskell program build and run using Cabal
Gary Johnson writes: > Guix System (unsurprisingly) has a built-in preference for building > packages with Guix. For building Haskell programs, check out the > `haskell-build-system`, which uses cabal and ghc under the hood. > > Also, if the package you want to install exists on Hackage > (https://hackage.haskell.org) but doesn't have a corresponding Guix > package, you should check out the Guix hackage importer: > > $ guix import hackage -r PACKAGE-NAME@VERSION > > This can auto-generate a Guix package definition for the corresponding > Hackage package that you can then use to install it through Guix. > > Finally, to answer your question about environment variables, you should > stick them in your home directory under your shell configuration script > (e.g., ~/.bashrc, ~/.bash_profile). Thank you for your helpful reply. These are the two lines I added to my `.bashrc` that resolve the error I was getting: ``` unset GHC_PACKAGE_PATH export LD_LIBRARY_PATH=/run/current-system/profile/lib/ ``` Note: The LD_LIBRARY_PATH variables was empty. If it was not I would have appended to the existing LD_LIBRARY_PATH variable.
Re: Haskell program build and run using Cabal
Hello, There are a few problems with the ghc ecosystem in guix right now (unless they have been fixed in the last month or so). The following is relevant to you. Our version of cabal-install is incompatible with the default ghc version: http://issues.guix.gnu.org/45055 The fix for this is to use ghc@8.6. From there you can use cabal as normal, but without the $GHC_PACKAGE_PATH variable set, i.e.: $ env -u GHC_PACKAGE_PATH cabal new-build I hope that helps. Kindly, John signature.asc Description: PGP signature
Re: Haskell program build and run using Cabal
Bone Baboon writes: > I am trying to build a Haskell program from source and run it. I am > using Cabal a Haskell build tool to do this. I am able to build and run > this program without the following error messages on other Linux > operating systems. > > [snip] > > Doing an internet search for this error message shows people dealing > with it by setting environment variables. > > With Cabal's `new-build` and `new-run` commands I am running into issues > with environment variables. Are environment variables managed in Guix > system configurations? I searched the Guix manual for the search term > "environment variable" and did not see a prominent section on > environment variables. That leads me to guess that in Guix environment > variables are left to configuration files in the users home directory. Guix System (unsurprisingly) has a built-in preference for building packages with Guix. For building Haskell programs, check out the `haskell-build-system`, which uses cabal and ghc under the hood. Also, if the package you want to install exists on Hackage (https://hackage.haskell.org) but doesn't have a corresponding Guix package, you should check out the Guix hackage importer: $ guix import hackage -r PACKAGE-NAME@VERSION This can auto-generate a Guix package definition for the corresponding Hackage package that you can then use to install it through Guix. Finally, to answer your question about environment variables, you should stick them in your home directory under your shell configuration script (e.g., ~/.bashrc, ~/.bash_profile). Happy hacking, Gary -- GPG Key ID: 7BC158ED Use `gpg --search-keys lambdatronic' to find me Protect yourself from surveillance: https://emailselfdefense.fsf.org === () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments Why is HTML email a security nightmare? See https://useplaintext.email/ Please avoid sending me MS-Office attachments. See http://www.gnu.org/philosophy/no-word-attachments.html
Haskell program build and run using Cabal
I am trying to build a Haskell program from source and run it. I am using Cabal a Haskell build tool to do this. I am able to build and run this program without the following error messages on other Linux operating systems. `cabal --version` outputs: ``` cabal-install version 2.4.0.0 compiled using version 2.4.0.1 of the Cabal library ``` I have installed GHC a Haskell compiler. When I run `ghc --version` it outputs: ``` The Glorious Glasgow Haskell Compilation System, version 8.6.5 ``` When I run `cabal new-build` it outputs: ``` cabal: Use of GHC's environment variable GHC_PACKAGE_PATH is incompatible with Cabal. Use the flag --package-db to specify a package database (it can be used multiple times). ``` After running `unset GHC_PACKAGE_PATH` I can build the program with `cabal new-build`. `unset GHC_PACKAGE_PATH` does not persist across different terminal emulator instances. Then when I try to run the program using `cabal new-run` I get this error message: ``` error while loading shared libraries: libgmp.so.10: cannot open shared object file: No such file or directory ``` I added `gmp` to my system configuration and reconfigured the system. However the error persists. The command `locate libgmp.so.10` shows that libgmp.so.10 is in the store. Doing an internet search for this error message shows people dealing with it by setting environment variables. With Cabal's `new-build` and `new-run` commands I am running into issues with environment variables. Are environment variables managed in Guix system configurations? I searched the Guix manual for the search term "environment variable" and did not see a prominent section on environment variables. That leads me to guess that in Guix environment variables are left to configuration files in the users home directory.
