I tried to create a Nix-style local build (v2-build) project on Cabal 3.0.
But several development tools (flycheck-haskell and doctest) don't work.
They worked on new-build project on Cabal 2.4.
Error message says they cannot find dependencies, as far as I read.
$ cabal v2-clean
$ cabal v2-build
$ cabal v2-test
Build profile: -w ghc-8.8.1 -O1
In order, the following will be built (use -v for more details):
- hstest9-0.1.0.0 (test:doctestd) (first run)
Configuring test suite 'doctestd' for hstest9-0.1.0.0..
Preprocessing test suite 'doctestd' for hstest9-0.1.0.0..
Building test suite 'doctestd' for hstest9-0.1.0.0..
[1 of 1] Compiling Main ( test/doctest-driver.hs, /Users/user/work/hstest9/dist-newstyle/build/x86_64-osx/ghc-8.8.1/hstest9-0.1.0.0/t/doctestd/build/doctestd/doctestd-tmp/Main.o )
Linking /Users/user/work/hstest9/dist-newstyle/build/x86_64-osx/ghc-8.8.1/hstest9-0.1.0.0/t/doctestd/build/doctestd/doctestd ...
Running 1 test suites...
Test suite doctestd: RUNNING...
/Users/user/work/hstest9/src/MyLib.hs:3:1: error:
Could not find module ‘Control.Effect’
Use -v (or `:set -v` in ghci) to see a list of the files searched for.
|
3 | import Control.Effect
| ^^^^^^^^^^^^^^^^^^^^^
Test suite doctestd: FAIL
Test suite logged to:
/Users/user/work/hstest9/dist-newstyle/build/x86_64-osx/ghc-8.8.1/hstest9-0.1.0.0/t/doctestd/test/hstest9-0.1.0.0-doctestd.log
0 of 1 test suites (0 of 1 test cases) passed.
cabal: Tests failed for test:doctestd from hstest9-0.1.0.0.
Your doctest doesn't find proper GHC_ENVIRONEMNT.
Since Cabal 3.0, cabal v2-build doesn't generate environment files by default.
Since Cabal 3.0, defaults to never. Before that, defaulted to creating them only when compiling with GHC 8.4.4 and older (GHC 8.4.4 is the first version that supports the -package-env - option that allows ignoring the package environment files).
https://www.haskell.org/cabal/users-guide/nix-local-build.html#cfg-field-write-ghc-environment-files
So you should set this option on v2-build.
$ cabal v2-build --write-ghc-environment-files=ghc8.4.4+
Or you can write this in $HOME/.cabal/config for default cabal behavior.
write-ghc-environment-files: ghc8.4.4+
Related
I want to build the haskell bindings for z3 in a Cabal project, the following is the minimum (faulty) example:
Using a project initialized by cabal init:
test/
- Main.hs
- Setup.hs
- CHANGELOG.md
- test.cabal
With modified test.cabal:
cabal-version: 3.0
name: z3-test
version: 0.1.0.0
extra-source-files: CHANGELOG.md
executable test
main-is: Main.hs
build-depends: base >=4.14 && <4.15
, z3 ^>=408.2
default-language: Haskell2010
Z3 binaries are located at C:\z3-4.8.5-x86-win.
Z3-bindings are installed:
cabal v1-install z3 --extra-lib-dirs=C:/z3-4.8.5-x64-win/bin --extra-include-dirs=C:/z3-4.8.5-x64-win/include -v3
All the requested packages are already installed:
z3-408.2
Use --reinstall if you want to reinstall anyway.
Now building the project using:
cabal v2-build --extra-lib-dirs=C:/z3-4.8.5-x64-win/bin --extra-include-dirs=C:/z3-4.8.5-x64-win/include -v3
Results in the error:
Build profile: -w ghc-8.10.2 -O1
In order, the following will be built (use -v for more details):
- z3-408.2 (lib) (requires build)
- z3-test-0.1.0.0 (exe:test) (first run)
Starting z3-408.2 (lib)
Failed to build z3-408.2. The failure occurred during the configure step.
Build log (
C:\cabal\logs\ghc-8.10.2\z3-408.2-1722a25655334afbca91ac935f14ff0d20ccf8c4.log
):
Configuring library for z3-408.2..
cabal.exe: Missing dependency on a foreign library:
* Missing (or bad) header file: z3.h
* Missing (or bad) C library: z3
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
library 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.
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.
cabal.exe: Failed to build z3-408.2 (which is required by exe:test from
z3-test-0.1.0.0). See the build log above for details.
How can I build a project with the z3 bindings?
Note that:
GHC version = 8.10.2
Cabal version = 3.2.0.0
I can only use cabal
Using cabal install ... or cabal v2-install ... results in Cannot build .. z3 because none of the components are available to build:
I'm getting an error that says the module doesn't exist when I try to runhaskell. It's odd because I try to install it first and says its up to date. Any idea how to fix this?
You could try creating the package environment in the local directory that holds your project, like this:
c:\Users\...\ex1haskell> cabal install --lib --package-env . QuickCheck
This should create a file of the form .ghc.environment.xxx in ex1haskell, which hopefully should be picked up by runhaskell/ghci/ghc invocations.
In ghci sessions, a sign that the environment is being picked up is the following message while starting:
Loaded package environment from ...
When the --package-env location is not given explicitly, a default location is used. According to the docs:
By default, it is writing to the global environment in
~/.ghc/$ARCH-$OS-$GHCVER/environments/default. v2-install provides the
--package-env flag to control which of these environments is modified.
But it seems that runhaskell is having problems to find the environment file in that default location.
Note. When creating a package environment, it's possible to specify multiple packages simultaneously, like this:
cabal install --lib --package-env . QuickCheck random aeson transformers
Also, package environments are just text files, so local environments can be deleted and recreated at will. The actual package binaries reside elsewhere and can potentially be reused by cabal.
A Common Environment
It is hard to debug if/when the actual tooling differs so let's first get a unified setup. I'll use docker to get GHC 8 and Cabal 3.x:
docker run --rm -it haskell bash
Understand that this isn't arbitrary or even preemptive. What you have shown - cabal install --lib ... and runhaskell ... does work for sane tool installations. You might have a bad installation or an old version of a tool that has different behavior.
Running a single file with runhaskell
Now we need a project:
root#8a934c302dba:/# mkdir Ex1
root#8a934c302dba:/# cd Ex1
root#8a934c302dba:/Ex1# cat <<EOF >Main.hs
> import Test.QuickCheck
>
> main :: IO ()
> main = print =<< (generate arbitrary :: IO Int)
> EOF
And test failure:
root#8a934c302dba:/Ex1# runhaskell Main.hs
Main.hs:1:1: error:
Could not find module `Test.QuickCheck'
Use -v (or `:set -v` in ghci) to see a list of the files searched for.
|
1 | import Test.QuickCheck
And install the library:
root#8a934c302dba:/Ex1# cabal update && cabal install --lib QuickCheck
And successful run:
root#8a934c302dba:/Ex1# runhaskell Main.hs
15
So my comment above was wrong - we don't need to explicitly list the package as it is already exposed after installation.
With the release of cabal-3, the packages from Hackage are installed in a new location that the compiler ghc and ghc-pkg know nothing about.
In other words, packages are installed but not registered for ghc. Ghci, ghc, ghc-pkg cannot work.
For example,
cabal install safe --lib
Create file t1.hs
import Safe
t1 = tailMay [1,2,3]
Let's try:
> ghci t1.hs
GHCi, version 8.10.2: https://www.haskell.org/ghc/:? for help
[1 of 1] Compiling Main (t1.hs, interpreted)
t1.hs: 1: 1: error:
Could not find module `Safe '
Use -v (or `: set -v` in ghci) to see a list of the files searched for.
|
1 | import Safe
| ^^^^^^^^^^^
Failed, no modules loaded.
This bug is described here
https://github.com/haskell/cabal/issues/6262
and here
https://gitlab.haskell.org/ghc/ghc/-/issues/17341
I use as a temporary solution setting a system variable
GHC_PACKAGE_PATH=C:\Users\me\AppData\Roaming\cabal\store\ghc-8.10.2\package.db;
(Windwos 10, haskell-dev by chocolatey)
via
On Windows, packages installed with cabal seem to be unavailable in ghc/ghci
but with updates I will have to manually change this system variable.
Are there any more elegant solutions to this problem?
P.S. Unfortunately, this solution (via GHC's environment variable GHC_PACKAGE_PATH) is incompatible with Cabal :(
https://github.com/haskell/cabal/issues/1944
One way to achieve this is to use the --env flag to make the libraries available to GHC whenever you are in the current directory:
~ $ mkdir /tmp/foo
~ $ cd /tmp/foo
/tmp/foo $ cabal install safe --lib --env .
Resolving dependencies...
Build profile: -w ghc-8.8.3 -O1
In order, the following will be built (use -v for more details):
- safe-0.3.19 (lib) (requires build)
Configuring library for safe-0.3.19..
Preprocessing library for safe-0.3.19..
Building library for safe-0.3.19..
…
> Installing library in /home/jojo/.cabal/store/ghc-8.8.3/incoming/new-4056/home/jojo/.cabal/store/ghc-8.8.3/safe-0.3.19-92fbaef88124b4508ce447f6245bc793f7a1748247ae68d10e449150df1069af/lib
t1.hs
/tmp/foo $ cat > t1.hs
import Safe
t1 = tailMay [1,2,3]
/tmp/foo $ ls -a
. .. .ghc.environment.x86_64-linux-8.8.3 t1.hs
/tmp/foo $ ghci t1.hs
GHCi, version 8.8.3: https://www.haskell.org/ghc/ :? for help
Loaded package environment from /tmp/foo/.ghc.environment.x86_64-linux-8.8.3
[1 of 1] Compiling Main ( t1.hs, interpreted )
Ok, one module loaded.
*Main>
Note that you probably shouldn’t do this in a directory where you actually have a foo.cabal file. See the documentation of cabal v2-install for details.
Working with GHC_ENVIRONMENT is better:
setx GHC_ENVIRONMENT C:\Users\me\.ghc\x86_64-mingw32-8.10.2\environments\default
it helps for ghc and ghci.
After, in C:\Users\me\AppData\Roaming\cabal\config we should add
package-db: C:\Users\me\AppData\Roaming\cabal\store\ghc-8.10.2\package.db
it helps for cabal.
Unfortunately, ghc-pkg still has problem and works with such flag:
ghc-pkg list --user-package-db="C:\Users\me\AppData\Roaming\cabal\store\ghc-8.10.2\package.db"
For Linux the steps are similar.
I tried running my program which uses Haskell QuickCheck via ghc MyProgramm.hs , but received the following error:
$ ghc Ex2.hs
[1 of 1] Compiling Ex2 ( Ex2.hs, Ex2.o )
Ex2.hs:21:1: error:
Could not find module ‘Test.QuickCheck’
There are files missing in the ‘QuickCheck-2.11.3’ package,
try running 'ghc-pkg check'.
Use -v to see a list of the files searched for.
|
21 | import Test.QuickCheck (
| ^^^^^^^^^^^^^^^^^^^^^^^^...
I installed stack, ran stack update and stack install QuickCheck without issue but the error persisted. Then, I ran cabal install QuickCheck and got the following errors:
$ cabal install QuickCheck
Resolving dependencies...
Configuring QuickCheck-2.12.4...
Building QuickCheck-2.12.4...
Failed to install QuickCheck-2.12.4
Build log ( /home/username/.cabal/logs/ghc-8.4.3/QuickCheck-2.12.4-3d2YDDqfPBn4BfmTJbpJXK.log ):
cabal: Entering directory '/tmp/cabal-tmp-9133/QuickCheck-2.12.4'
Configuring QuickCheck-2.12.4...
Preprocessing library for QuickCheck-2.12.4..
Building library for QuickCheck-2.12.4..
[ 1 of 16] Compiling Test.QuickCheck.Exception ( Test/QuickCheck/Exception.hs, dist/build/Test/QuickCheck/Exception.o )
[ 2 of 16] Compiling Test.QuickCheck.Random ( Test/QuickCheck/Random.hs, dist/build/Test/QuickCheck/Random.o )
Test/QuickCheck/Random.hs:10:1: error:
Could not find module ‘System.Random’
There are files missing in the ‘random-1.1’ package,
try running 'ghc-pkg check'.
Use -v to see a list of the files searched for.
|
10 | import System.Random
| ^^^^^^^^^^^^^^^^^^^^
Test/QuickCheck/Random.hs:11:1: error:
Could not find module ‘System.Random.TF’
There are files missing in the ‘tf-random-0.5’ package,
try running 'ghc-pkg check'.
Use -v to see a list of the files searched for.
|
11 | import System.Random.TF
| ^^^^^^^^^^^^^^^^^^^^^^^
Test/QuickCheck/Random.hs:12:1: error:
Could not find module ‘System.Random.TF.Gen’
There are files missing in the ‘tf-random-0.5’ package,
try running 'ghc-pkg check'.
Use -v to see a list of the files searched for.
|
12 | import System.Random.TF.Gen(splitn)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
cabal: Leaving directory '/tmp/cabal-tmp-9133/QuickCheck-2.12.4'
cabal: Error: some packages failed to install:
QuickCheck-2.12.4-3d2YDDqfPBn4BfmTJbpJXK failed during the building phase. The
exception was:
ExitFailure 1
However, I already have the arch packages haskell-random, haskell-tf-random and haskell-mwc-random installed. Does anybody know how to fix this?
Edit: I also ran cabal install random --reinstall.
Problem
On Archlinux as of 2022-09-17, pacman -S ghc cabal-install will install
system packages that provide only dynamic files (.so, .dyn_hi) in
installed packages inside /usr/lib/ghc-*; static files (.a, .hi) are (for
the most part) missing. However, the default cabal configuration enables static file
building. Unfortunately, upstream cabal-install doesn't track whether or not
static files are available inside installed packages. It just assumes they
are, and when they are gone, it fails with errors such as you have found:
[1 of 1] Compiling Main ( Main.hs, ../setup.dist/work/depender/dist/build/depender/depender-tmp/Main.o )
Main.hs:3:1: error:
Could not find module `Dynamic'
There are files missing in the `dynamic-1.0' package,
try running 'ghc-pkg check'.
Use -v (or `:set -v` in ghci) to see a list of the files searched for.
|
| import qualified Dynamic (number)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Workaround
A quick workaround just to get up and running quickly is to disable static file
building, which is by default enabled. (Note that trying to pass package-local
flags to disable static file with e.g. --enable-shared --enable-executable-dynamic --disable-library-vanilla (which is how most if
not all current Archlinux Haskell packages seem to build packages, e.g. with
https://github.com/archlinux/svntogit-community/blob/master/haskell-scientific/trunk/PKGBUILD)
building using cabal-install may be ignored due to another, related bug; but
~/.cabal/config is a safe bet.) You may do so by adding 3 lines to
~/.cabal/config in the appropriate location:
library-vanilla: False
shared: True
executable-dynamic: True
(Alternatively, consider using alternative tools like stack.)
More complete solution
For a more long-term solution, one option involves 2 pieces: 1) one or more
system packages that provide all types of build artifacts, static and dynamic,
for the base, foundational packages (from GHC and cabal-install), at least as an option besides dynamic-only packages (secondary Haskell packages are optional,
since cabal-install can rebuild these with needed build artifacts (static or
dynamic)), and 2) patching cabal-install (and ghc-pkg, which can handle .conf
files recording information about installed packages) to track whether static
files are available, and to be aware of these when resolving dependencies so
that cabal-install knows when to prefer rebuild a source package with needed
build artifact configuration over an already installed package that doesn't
provid required build artifacts.
There is a merge request (I submitted) that provides such a patchset, called
fix-dynamic-deps, at https://github.com/haskell/cabal/pull/8461. For users
running into exactly the problem that you described (myself included), I also
created an AUR package that provides both pieces based on GHC 9.4.2 with Cabal
3.9.0.0 that includes my patchset (there is a mirror at
https://github.com/bairyn/ghc-cabal-arts.) It provides ghc and
cabal-install but includes both of these pieces.
Further reading
Here are a few more resources I wrote on or are related to this bug:
https://wiki.archlinux.org/index.php?title=Haskell&diff=745459&oldid=738269#Troubleshooting
https://github.com/haskell/cabal/pull/8461
https://github.com/bairyn/ghc-cabal-arts
https://github.com/bairyn/cabal/tree/fix-dynamic-builds
Even though I have a main = do and couldn't get it working that way, I was able to run my QuickCheck test as follows:
To run a quickCheck, first load your program with:
$ ghci MyProg.hs
Then to run the quickCheck, find the test you want to run, then run it with:
$ quickCheck my_quick_check
I was setting up a yesod scaffolded site using the yesod init command, and I named my project yesodtry. I proceeded to setup a scaffolded site using this command, which was given by yesod init:
cd yesodtry && cabal sandbox init && cabal install && yesod devel
Everything went smoothly, and I accessed the demo site at 127.0.0.1:3000. Out of curiosity, I tried to try the yesod test command. Here's the output I got:
Resolving dependencies...
Configuring yesodtry-0.0.0...
cabal: At least the following dependencies are missing:
hspec -any, yesod-test ==1.2.*
Seeing how the yesodtry.cabal file has a test section, I tried executing cabal build test, and this is the output:
cabal: Cannot build the test suite 'test' because test suites are not enabled.
Run configure with the flag --enable-tests
Ok... so it tells me to run cabal configure --enable-tests. And here's the output:
Resolving dependencies...
Configuring yesodtry-0.0.0...
cabal: At least the following dependencies are missing:
hspec -any, yesod-test ==1.2.*
I see this line in yesodtry.cabal, for the build-depends of the test-suite test "section":
yesod-test >= 1.2 && < 1.3
It seems like cabal is not installing the dependencies here. How do I do that?
Thank you.
Ok, I think I found the answer on this Haskell-cafe thread.
We have to do:
cabal configure --enable-tests
cabal install --only-dependencies --enable-tests
And the dependencies for the test-suite test section will be installed.
I then ran yesod test, and here's the last few lines of the output:
Linking dist/build/test/test ...
Building yesodtry-0.0.0...
Preprocessing library yesodtry-0.0.0...
In-place registering yesodtry-0.0.0...
Preprocessing test suite 'test' for yesodtry-0.0.0...
Linking dist/build/test/test ...
Running 1 test suites...
Test suite test: RUNNING...
Test suite test: PASS
Test suite logged to: dist/test/yesodtry-0.0.0-test.log
1 of 1 test suites (1 of 1 test cases) passed.
Hopefully this will help anyone who encounters the same problem in the future.