[Haskell-cafe] data-accessor-template-0.2.1.3 breaks cabal-install
jwlato at gmail.com
Fri Feb 12 22:30:20 EST 2010
I've recently run across an odd situation. I have a brand new install
of GHC-6.12.1 (just did a fresh install of OSX 10.6), and am
reinstalling some libraries. I've run into an unusual problem. I'm
not sure if this would be considered a cabal bug or not, but I don't
think it's a good situation.
data-accessor-template depends upon template-haskell (>=2.2 && <2.4),
unless built with the flag -ftemplate_2_4, in which case it depends
upon template-haskell 2.4 (appropriate for ghc-6.12.1). The relevant
lines of the .cabal file are:
description: Adapt to TemplateHaskell version of GHC-6.12
Build-Depends: template-haskell >=2.4 && <2.5
Build-Depends: template-haskell >=2.2 && <2.4
I can install data-accessor-template when the template_2_4 flag is
used, but then when I try to install a package that depends upon
data-accessor-template cabal-install calculates the template-haskell
>=2.2 && <2.4 dependency and attempts to fulfill it. Which fails at
packedstring (can't find Data.Data in a hidden base package).
I've included output from attempting to install Chart that
demonstrates the behavior. Note that even though cabal-install sees
data-accessor-template as installed, it attempts to reinstall it.
John-Latos-MacBook:packages johnlato$ cabal install -v -O Chart
In order, the following would be installed:
packedstring-0.1.0.1 (new package)
template-haskell-18.104.22.168 (new version)
data-accessor-template-0.2.1.3 (reinstall) changes: template-haskell-22.214.171.124
Chart-0.12 (new package)
This affects everything down the dependency tree, notably Chart,
criterion, and yi.
I can work around this by specifying a previous version of
data-accessor-template, but unfortunately I don't know how to address
the real problem.
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