CODEWITHSUNDEEP
haskellelmcabal
john mangual
john mangual

Reputation: 8172

cabal: Encountered missing dependencies:

I am trying to install a Haskell program (itself a compiler for another programming language) from the Github repository.

The Elm compiler is itself a Haskell program and I would like to compile it from source:

$ cabal configure
Resolving dependencies...
Warning: solver failed to find a solution:
Could not resolve dependencies:
trying: elm-0.19.1 (user goal)
next goal: zip-archive (dependency of elm-0.19.1)
Dependency tree exhaustively searched.
Trying configure anyway.
Configuring elm-0.19.1...
cabal: Encountered missing dependencies:
SHA -any,
ansi-terminal ==0.8.*,
ansi-wl-pprint >=0.6.8 && <0.7,
containers >=0.5.8.2 && <0.6,

If I try to use a different command the computer searches for a different version of the Elm programming language.

$ cabal install elm
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: Elm-0.13 (user goal)
trying: base-4.12.0.0/installed-4.1... (dependency of Elm-0.13)
next goal: transformers (dependency of Elm-0.13)
rejecting: transformers-0.5.6.2/installed-0.5..., transformers-0.6.0.2,
transformers-0.5.6.2, transformers-0.5.5.2, transformers-0.5.5.0,
transformers-0.5.4.0, transformers-0.5.2.0, transformers-0.5.1.0,
transformers-0.5.0.1, transformers-0.5.0.0 (conflict: Elm => transformers>=0.2
&& <0.5)
rejecting: transformers-0.4.3.0, transformers-0.4.2.0 (conflict:

I already have Elm installed globally and I would like to install a local copy that I cloned from Github. The cabal documentation doesn't say much.

Helpful information:

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.6.5
$ cabal --version
cabal-install version 1.24.0.2
compiled using version 1.24.2.0 of the Cabal library

Trying different things possibly at risk:

$ cabal install --only-dependencies
Resolving dependencies...
internal error: could not construct a valid install plan.
The proposed (invalid) plan contained the following problems:
Package time is required by several packages, but they require inconsistent
versions:
package zip-archive-0.3.3 requires time-1.10
package snap-server-1.1.2.0 requires time-1.10
package snap-core-1.0.4.2 requires time-1.10
package io-streams-1.5.2.1 requires time-1.10
package http-client-0.6.4.1 requires time-1.10
package elm-0.19.1 requires time-1.10
package directory-1.3.6.2 requires time-1.10
package cookie-0.4.5 requires time-1.10
package HTTP-4000.3.16 requires time-1.10
package unix-2.7.2.2 requires time-1.8.0.2

Proposed plan:
Configured HTTP-4000.3.16 (.fake.HTTP-4000.3.16)
Configured SHA-1.6.4.4 (.fake.SHA-1.6.4.4)
Configured ansi-terminal-0.8.2 (.fake.ansi-terminal-0.8.2)
Configured ansi-wl-pprint-0.6.8.2 (.fake.ansi-wl-pprint-0.6.8.2)
Configured asn1-encoding-0.9.6 (.fake.asn1-encoding-0.9.6)
Configured asn1-parse-0.9.5 (.fake.asn1-parse-0.9.5)
Configured asn1-types-0.3.4 (.fake.asn1-types-0.3.4)

Upvotes: 1

Views: 2001

Answers (1)

Daniel Wagner
Daniel Wagner

Reputation: 153342

Your cabal is very old, and I strongly recommend you upgrade.

That said... with cabal-1, the invocation is simply

cabal install

with no elm at the end. Run it from within the directory you cloned from github that has a file named elm.cabal or similar -- it will automatically look for a file with extension .cabal and install the package described inside. cabal install will also take care of installing the missing dependencies.

With modern cabal, and assuming the executable named in the .cabal file is called elm, I would use

cabal run elm -- --args --for --elm --compiler

to run the compiler during testing, and then

cabal install --exe

when you are satisfied with your changes and want to make the executable available more widely.

Upvotes: 2

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