I have been trying for the past 3 days to learn how can I install packages to use in my haskell program.
I need a package called:
https://hackage.haskell.org/package/Chart-cairo
in order to start using:
https://github.com/timbod7/haskell-chart
I know its probably a silly question, but could someone explain how to install/build an haskel package with stack ?
Thank you!
To install package using stack simply type stack install packagename. Remember to register it in package.yaml as dependency in your project, otherwise it won't be visible.
In your case:
stack install Chart-cairo
and in package.yaml:
dependencies:
- ...
- Chart-cairo >= 1.9
Related
I want to install the Haskell libary hip from https://hackage.haskell.org/package/hip by using stack. This does not work, because stack seems to not being able to install dependencies.
I have stack freshly installed by curl -sSL https://get.haskellstack.org/ | sh, and stack --version gives me
Version 1.9.3, Git revision 40cf7b37526b86d1676da82167ea8758a854953b (6211 commits) x86_64 hpack-0.31.1
I have tried several things like another resolver, reinstalling different versions of stack, ghc or cabal.
I have tried stack new test, and inside the test folder, i wrote stack install hip.
I got the following error:
Error: While constructing the build plan, the following exceptions were
encountered:
In the dependencies for hip-1.5.3.0:
Chart must match >=1.5, but the stack configuration has no specified
version (latest matching version is 1.9)
Chart-diagrams must match >=1.5, but the stack configuration has no
specified version (latest matching version is 1.9)
needed since hip is a build target.
Some different approaches to resolving this:
* Consider trying 'stack solver', which uses the cabal-install solver to
attempt to find some working build configuration. This can be convenient
when dealing with many complicated constraint errors, but results may be
unpredictable.
* Recommended action: try adding the following to your extra-deps
in /home/jarek/Desktop/test/stack.yaml:
Chart-1.9#sha256:f41568b6b3704f66c2ec163295b430ab7d798f91de426c2d5aba747d1135cd9b
Chart-diagrams-1.9#sha256:cdd0c22d730e507f9644e690833096ee127302b5ff5e1571f6def419160a2642
Plan construction failed.
I expect something like:
Building dependencies...
Installing Chart-1.9
...
...
...
hip successfully installed.
Please tell me if i did not provide all infos necessary for you to help me with my problem.
Installing with the resolver lts-7.5 works.
Why not do what stack recommended?
Recommended action: try adding the following to your extra-deps
in /home/jarek/Desktop/test/stack.yaml:
Chart-1.9#sha256:f41568b6b3704f66c2ec163295b430ab7d798f91de426c2d5aba747d1135cd9b
Chart-diagrams-1.9#sha256:cdd0c22d730e507f9644e690833096ee127302b5ff5e1571f6def419160a
It's the easiest way to accomplish your goal.
Update: lts-10.10 is the most recent resolver to include hip. If you update your stack.yaml to use lts-10.10 and add hip in your .cabal file, you should be good to go.
I'm totally new in haskell, and trying to install hfmt using stack.
stack install hfmt
but it shows
Error: While constructing the build plan, the following exceptions were encountered:
In the dependencies for hfmt-0.2.0:
hindent-4.6.4 must match ==5.* (latest applicable is 5.2.5)
hlint-1.9.35 must match ==2.* (latest applicable is 2.0.15)
stylish-haskell-0.6.1.0 must match ==0.8.* (latest applicable is 0.8.1.0)
needed for unknown reason - stack invariant violated.
So, I tried to re-install hindent , hlint and stylish-haskell again.
However I couldn't find any command - stack upgrade or stack update.. even I failed to remove these packages.
Could you help install/update these package?
With reports like this, it's best to include the output of stack --version to know what version of the tool you're using. Also, how you installed Stack can be useful information.
As for hfmt: there's no version of it present in a Stackage snapshot, which you can see here:
https://www.stackage.org/package/hfmt
On my machine, I was able to build successfully against LTS 10.3, using this command:
stack install hfmt-0.2.0 --resolver lts-10.3
I'm trying to setup a new project using the nightly-2017-08-17 snapshot
stack new test --resolver nightly-2017-08-17
However this gives the following error:
Downloading template "new-template" to create project "test" in test/ ...
Looking for .cabal or package.yaml files to use to init the project.
Using cabal packages:
- test/test.cabal
Selected resolver: nightly-2017-08-17
Unable to parse cabal file: FromString "This package requires at least Cabal version 2.0" Nothing
Cabal is in its latest version:
stack setup --upgrade-cabal
Currently installed Cabal is 2.0.0.2, newest is 2.0.0.2. I'm not upgrading Cabal.
stack will use a sandboxed GHC it installed
For more information on paths, see 'stack path' and 'stack exec env'
To use this GHC and packages outside of a project, consider using:
stack ghc, stack ghci, stack runghc, or stack exec
Is this not the correct way of selecting this nightly snapshot with stack or is this a bug in the tool?
Cabal's file format has changed in the 2.0 release of it (likely because of backpack). You have to use Stack version >= 1.5.1 which bypasses this error. A proper fix for this will be likely released in the next version of Stack. IIRC, the fix is already in the master brach of the stack - so the upgrade via --source-only willl also work for you.
You can read the changelog here to know more information about it.
I'm trying to set up Hakyll on a fresh Ubuntu 16.04 instance, but I can't seem to get the Stack-based setup instructions right.
Starting out with stack install hakyll, I get:
Error: While constructing the build plan, the following exceptions were encountered:
In the dependencies for hakyll-4.9.3.0:
http-conduit-2.1.11 must match >=2.2 && <2.3 (latest applicable is 2.2.3)
Plan construction failed.
I got a similar error when tying to stack-install http-conduit-2.1.11, this time with:
Error: While constructing the build plan, the following exceptions were encountered:
In the dependencies for http-conduit-2.2.3:
http-client-0.4.31.2 must match >=0.5 && <0.6 (latest applicable is 0.5.5)
http-client-tls-0.2.4.1 must match >=0.3 && <0.4 (latest applicable is 0.3.3.1)
Plan construction failed.
After resolving dependencies for this (also using Stack), I tried once again to stack install http-conduit-2.1.11, but I once again got the same dependency error.
The packages http-client-0.4.31.2 and http-client-tls-0.2.4.1 appear in my ~/.stack/precompiled/x86_64-linux/ghc-8.0.1/1.24.0.0/, which isn't explicitly in my $PATH, however that feels like an extremely hacky solution, and I haven't found any documentation recommending this approach.
How can I correctly install Hakyll on my machine?
Dependency management with stack is meant to be reproducible and declarative, that means that a stack project will only compile once all dependencies are recorded in the .cabal file(s) of the project and once the stack.yaml of the project defines versions for these dependencies either in the resolver or the extra-deps section.
Your confusion seems to stem from a misunderstanding of what stack install does. The command line help has this to say about it:
build Build the package(s) in this directory/configuration
install Shortcut for 'build --copy-bins'
...
--[no-]copy-bins Enable/disable copying binaries to the local-bin-path
(see 'stack path')
stack install does not save any dependencies.
So the proper way of making hakyll available as a dependency to your code is:
Create a proper stack project with stack init if you already have a Cabal package, or stack new if you don't.
Add hakyll to the library or executable build-depends in your .cabal file.
Attempt to stack build and follow the instructions in any error messages until all issues are resolved.
A simpler solution than #sjakobi's in this case was to specify a resolver as a command line option when starting a new Stack project:
stack install hakyll --resolver=5.11 --install-ghc
Using cabal, I could install hakyll with the command:
cabal install hakyll
How can I do the same thing using stack?
stack install hakyll
stack offers a curated set of packages that won't blow your machine up. If you want to check what packages are available, or exactly what version is supported, or on what version of GHC you can get it, check out https://www.stackage.org/.
For example, you can get hakyll 4.6.9.0 right now for both GHC 7.8.4 and GHC 7.10.1. Pretty neat. - source
EDIT: I forgot to mention, Yuan Wang's method works for getting the version of hakyll that is not curated into stackage. It's up to you what version you need.
add hakyll in stack.yaml generated by stack init or stack new
yaml file should look like:
flags: {}
packages:
- '.'
extra-deps:
- hakyll-4.7.1.0
resolver: lts-2.15
after that, run stack solver installs it
https://github.com/commercialhaskell/stack/wiki/stack.yaml
This documentation worked for me
On package.yaml add the library under dependencies, for example:
dependencies:
- base >= 4.7 && < 5
- hakyll # added here