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

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 depencencies seem redundant:

 - criterion-0.6.2.0-9dd4d764629a47662168743b2dfda9bc
Versions [faq] 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 && <4.8), Cabal (>=1.14 && <1.21), cmdargs (==0.10.*), directory (>=1.1 && <1.3), filepath (==1.3.*), haskell-src-exts (>=1.13 && <1.16) [details]
License BSD-3-Clause
Copyright © 2014 Herbert Valerio Riedel
Author Herbert Valerio Riedel
Maintainer Herbert Valerio Riedel <hvr@gnu.org>
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 Sat Apr 26 15:25:56 UTC 2014
Distributions NixOS:0.1.2
Executables packunused
Downloads 5354 total (142 in the last 30 days)
Rating 2.0 (votes: 1) [estimated by rule of succession]
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Status Hackage Matrix CI
Docs not available [build log]
Last success reported on 2015-06-06 [all 6 reports]

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