packunused: Tool for detecting redundant Cabal package dependencies

[ bsd3, distribution, program ] [ Propose Tags ]

This simple CLI tool allows to find out which of the packages listed as build-depends in a Cabal package description file are redundant.

packunused works by taking advantage of GHC's -ddump-minimal-imports feature which creates .import files for each compiled module containing a minimal set of explicit import declarations. These .import files together with Cabal's generated package configuration meta-data is analyzed by packunused to detect potentially redundant package dependencies.

In order to use packunused you have to configure the package as usual. See the example session below:

cabal clean
rm *.imports
cabal configure -O0 --disable-library-profiling
cabal build --ghc-option=-ddump-minimal-imports
packunused

Experimental support for stack:

stack setup --upgrade-cabal  # necessary only when stack's global Cabal installation is out of date
stack clean
stack build --ghc-options '-ddump-minimal-imports -O0'
packunused

The -O0 --disable-library-profiling options are just to speed up compilation. In some cases you might want to pass additional options to the configure step, such as --enable-benchmark or --enable-tests.

When run, packunused prints a report to standard output listing its findings for each component built. The following is an example for the packunused package itself, with a redundant dependency added for demonstration on purpose:

detected package components
~~~~~~~~~~~~~~~~~~~~~~~~~~~

 - executable(s): packunused

(component names suffixed with '*' are not configured to be built)

executable(packunused)
~~~~~~~~~~~~~~~~~~~~~~

The following package dependencies seem redundant:

 - criterion-0.6.2.0-9dd4d764629a47662168743b2dfda9bc
Versions 0.1.0.0, 0.1.0.1, 0.1.1.0, 0.1.1.1, 0.1.1.2, 0.1.1.3, 0.1.1.4, 0.1.2
Change log changelog.md
Dependencies base (>=4.5 && <4.10), Cabal (==1.24.*), directory (>=1.1 && <1.4), filepath (>=1.3 && <1.5), haskell-src-exts (>=1.18.2 && <1.20), optparse-applicative (>=0.8 && <0.14), process (>=1.1 && <1.7), split (==0.2.*) [details]
License BSD-3-Clause
Copyright © 2014 Herbert Valerio Riedel
Author Herbert Valerio Riedel
Maintainer Herbert Valerio Riedel <hvr@gnu.org>
Revised Revision 1 made by HerbertValerioRiedel at Sat Jun 3 11:13:25 UTC 2017
Category Distribution
Home page https://github.com/hvr/packunused
Bug tracker https://github.com/hvr/packunused/issues
Source repo head: git clone https://github.com/hvr/packunused.git
Uploaded by HerbertValerioRiedel at Fri May 5 16:38:49 UTC 2017
Distributions NixOS:0.1.2
Executables packunused
Downloads 4903 total (25 in the last 30 days)
Rating 2.0 (votes: 1) [estimated by rule of succession]
Your Rating
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Status Docs not available [build log]
Last success reported on 2017-05-05 [all 2 reports]
Hackage Matrix CI

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Note: This package has metadata revisions in the cabal description newer than included in the tarball. To unpack the package including the revisions, use 'cabal get'.

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