我试图让Cabal安装
haskell-src-Meta包,而且我对模板-haskell依赖有困难. haskell-src-Meta的依赖包括两者
template-haskell >=2.7 && <2.9,template-haskell >=2.4 && <2.7,
碰巧模板-haskell版本2.7及更高版本将不会安装在我的系统上,但将安装template-haskell 2.5.0.0.
当我要求Cabal安装haskell-src-Meta时,如何告诉它使用template-haskell == 2.5.0.0？
以下是我系统中cabal info haskell-src-Meta的完整信息：
* haskell-src-Meta (library) Synopsis: Parse source to template-haskell abstract Syntax. Latest version available: 0.5.1 Latest version installed: [ Not installed ] Homepage: [ Not specified ] Bug reports: https://github.com/benmachine/haskell-src-Meta/issues Description: The translation from haskell-src-exts abstract Syntax to template-haskell abstract Syntax isn't 100% complete yet. Category: Language License: BSD3 Author: Matt Morrow Maintainer: Ben Millwood <haskell@benmachine.co.uk> Source repo: git://github.com/benmachine/haskell-src-Meta.git Flags: new-th Dependencies: base >=4.2 && <4.6,haskell-src-exts >=1.8 && <1.12,pretty >=1.0 && <1.2,syb >=0.1 && <0.4,th-lift ==0.5.*,template-haskell >=2.7 && <2.9,uniplate >=1.3 && <1.7 Cached: No Modules: Language.Haskell.Meta Language.Haskell.Meta.Parse Language.Haskell.Meta.Parse.Careful Language.Haskell.Meta.Syntax.Translate Language.Haskell.Meta.Utils Language.Haskell.TH.Instances.Lift
cabal install --constraint="template-haskell == 2.5.0.0" haskell-src-Meta
