Within my project's .cabal file I've got the following under the executable section:
executable ArchPkgstatsScraper
hs-source-dirs: app
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, ArchPkgStatsScraper
, text
, conduit
, html-conduit
, http-conduit
, xml-conduit
, resourcet
, transformers
After I've successfully installed / built the above with stack, how could I check which version of xml-conduit is installed?
The command
stack ls dependencies
or for older version of stack:
stack list-dependencies
will list every dependency installed for the current project, along with its version.
The new command is going to be
stack ls dependencies
which is replacement of stack list-dependencies
You can read more about it here
Related
I'm using inline-c and I have two C files that I'd like to call in the Haskell code. In the Cabal file, there are:
include-dirs: cbits
, /usr/local/include
c-sources: cbits/genann.c
In the Cbits directory, there's also genann.h
I can build and run the project without problem but when I do cabal install, the compiler complain that it can't find the C header file.
I checked the Cabal manual and added the following options:
includes: cbits/genann.h
install-includes: cbits/genann.h
This time I got:
Configuring executable 'inline-gsl' for inline-gsl-0.1.0.0..
cabal-3.6.2.0: Missing dependency on a foreign library:
* Missing (or bad) header file: cbits/genann.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
Where is wrong here? Do I need to compile the C code into object code and put them in the system?
The complete Cabal file:
cabal-version: 2.4
name: inline-gsl
version: 0.1.0.0
-- A short (one-line) description of the package.
-- synopsis:
extra-source-files: CHANGELOG.md
executable inline-gsl
main-is: Main.hs
build-depends: base ^>=4.14.3.0
, inline-c
, vector
, massiv
, array
, bytestring >= 0.10
, template-haskell
hs-source-dirs: app
pkgconfig-depends: glib-2.0, gtk4, gsl
default-language: Haskell2010
extra-libraries: m, tensorflow
extra-lib-dirs: /usr/local/lib
cc-options: -Wall -m64 -O4
include-dirs: cbits
, /usr/local/include
includes: cbits/genann.h
install-includes: cbits/genann.h
c-sources: cbits/genann.c
I can build and run the project without problem but when I do cabal install, the compiler complain that it can't find the C header file.
I believe this indicates that the problem is that your header files are not included in your package source tarballs (sdist). You need to list all non-Haskell source files under the extra-source-files field in your cabal file:
extra-source-files: CHANGELOG.md, cbits/genann.h, cbits/genann.c
I am very new to Haskell and I am trying to add the graphics package gloss to my stack project but I am encountering problems when doing stack build.
I have created my stack project as follows:
LICENSE package.yaml stack.yaml
README.md package.yaml~ stack.yaml.lock
Setup.hs project39.cabal stack.yaml~
TAGS project39.cabal~ test
and edited the stack.yamland the cabal file as follows:
# extra-deps:
# - acme-missiles-0.3
# - git: https://github.com/commercialhaskell/stack.git
# commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
# - gloss-1.13.2.1
executable project39-exe
main-is: Main.hs
other-modules:
Paths_project39
hs-source-dirs:
app
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends:
base >=4.7 && <5
, project39
, gloss
default-language: Haskell2010
In the src file Lib.hs I have added a Import Graphics.Gloss to test if it works:
module Lib
( someFunc
) where
import Graphics.Gloss
but when I then do stack build I get the following error:
Could not load module ‘Graphics.Gloss’
It is a member of the hidden package ‘gloss-1.13.2.1’.
Perhaps you need to add ‘gloss’ to the build-depends in your .cabal file.
Use -v (or `:set -v` in ghci) to see a list of the files searched for.
|
4 | import Graphics.Gloss
| ^^^^^^^^^^^^^^^^^^^^^
I am unsure what the problem here is and how to solve it.
You have a separate library stanza in your package.yaml. You need to add the gloss dependency there.
I'm trying to build a Haskell project using Cabal. I have a file src/Main.hs which contains the module Main and a function main. That file runs the web interface of my app. And I have another file, src/CLI.hs which contains the module CLI and a function main. I can run it just fine with runhaskell CLI ..., but I can't seem to compile it using cabal.
The thing is, even if I specify CLI.hs as the main file (main-is: CLI.hs), it still compiles the project with the main from src/Main.hs, thereby giving me the web app instead of the CLI.
I want to be able to compile two executables, one which is the web app, and one which is the CLI, specifying the entry points of each as main in CLI.hs and main in Main.hs, respectively.
Here's the segment of the .cabal file I'm using at the moment:
executable color-word-analyzer-cli
main-is: CLI.hs
other-modules: AnnotateColors
, CategorizeColor
, ColorMaps
, FindColors
, PlotColors
, Types
, Main
build-depends: base
, lucid
...
, wai-middleware-static
hs-source-dirs: src/
default-language: Haskell2010
executable color-word-analyzer-web
main-is: Main.hs
other-modules: AnnotateColors
, CategorizeColor
, ColorMaps
, FindColors
, PlotColors
, Types
, CLI
build-depends: base
, lucid
...
, wai-middleware-static
hs-source-dirs: src/
default-language: Haskell2010
Which throws the error (among others):
Building executable 'color-word-analyzer-cli' for color-word-analyzer-0.1.0.0..
Warning: Enabling workaround for Main module 'Main' listed in 'other-modules'
illegally!
<no location info>: warning: [-Wmissing-home-modules]
These modules are needed for compilation but not listed in your .cabal file's other-modules:
Main
which is funny, since Main is clearly listed there in other-modules.
I'm using cabal version 3.0.0.0, and ghc version 8.8.2.
The fully explicit form of a compilation unit is <package>:<category>:<ident> where in the case the packages is color-word-analyzer, category is exe and ident is the executables. So for your case you can call:
cabal build color-word-analyzer:exe:color-word-analyzer-cli color-word-analyzer:exe:color-word-analyzer-web
Now you don't actually need to specify all of that. When the executable is unique the fact that it is an executable (and not, say, a test from some other package or another package name itself) and the fact that it is from color-word-analyzer is clear in this context. You can therefore call:
cabal build color-word-analyzer-cli color-word-analyzer-web
EDIT: because your link didn't have a stanza for -web I used one of my own creation which didn't include the CLI module. Notice your CLI file is module Main so that explains the error you see - you can't include a module Main as a library module.
Background
I'm building a logfile parser in Haskell. I'm using stack to build it. Running the stack build command works happily and my project compiles. Running stack test, however, produces the following error:
parser-test: executable not found
I see the the following warning above the error message but I don't know how to avoid the redirect to which it refers.
Warning: output was redirected with -o, but no output will be generated because there is no Main module.
Relevant files
I haven't written any tests yet so the test file is as it was created by stack new. My cabal file looks like this:
...
category: Executable
build-type: Simple
-- extra-source-files:
cabal-version: >=1.10
library
hs-source-dirs: src
exposed-modules: LogParser
build-depends: base >= 4.7 && < 5
, attoparsec
, bytestring
, old-locale
, time
default-language: Haskell2010
executable parser-exe
hs-source-dirs: app
main-is: Main.hs
ghc-options: -threaded -rtsopts -with-rtsopts=-N
build-depends: base
, attoparsec
, bytestring
, old-locale
, time
, parser
default-language: Haskell2010
test-suite parser-test
type: exitcode-stdio-1.0
hs-source-dirs: test
main-is: Spec.hs
build-depends: base
, attoparsec
, bytestring
, hspec
, hspec-attoparsec
, old-locale
, time
, parser
ghc-options: -threaded -rtsopts -with-rtsopts=-N
default-language: Haskell2010
source-repository head
type: git
...
I presume I'm missing something but I can't find where what I'm missing is documented.
Desired behaviour
I should see the Test suite not yet implemented message outlined in the stack documentation.
The content of the test/Spec.hs file from the template is:
main :: IO ()
main = putStrLn "Test suite not yet implemented"
You can see this content at commercialhaskell/stack-templates in new-template.hsfiles.
I'm not sure where the module ParserSpec where line comes from (as brought up in the Github issue), but it's not part of the template. On my system, stack new bar && cd bar && stack test succeeds.
As to the reason behind the Main module requirement: it comes from the Cabal library, and as I understand it was added due to limitations in other compilers Cabal supports. In other words, GHC could technically allow this code to compile, but Cabal does not pass in those arguments to remain compatible with other compilers.
I'm working on a website using Yesod I have the normal build running but I can't seem to populate my database reliably. I have a second haskell program that populates the database and I've added it to my cabal file like this:
executable program
if flag(library-only)
Buildable: False
main-is: ../main.hs
hs-source-dirs: dist
build-depends: base
, myproject
, yesod-default
executable init
if flag(library-only)
Buildable: False
main-is: init.hs
hs-source-dirs: Init
build-depends: base
, directory
, persistent
, persistent-sqlite
, text
, myproject
, yesod-default
The problem is that when I run 'cabal build' it does not rebuild init when init.hs changes. What do I have to do to make this happen?
Here's an example terminal session (after editing init.hs):
$ cabal build
Building myproject-0.0.0...
Preprocessing library myproject-0.0.0...
Registering myproject-0.0.0...
$ rm -rf dist/build/myproject/init
$ cabal build
Building myproject-0.0.0...
Preprocessing library myproject-0.0.0...
Registering myproject-0.0.0...
Thank you.
You can manage multiple executables by passing them as arguments to cabal build and cabal run. For example, cabal build init. The first executable is the default if no target name is given.