Stack/Cabal找不到快乐

Question

我试图用Haskell Stack建立the code from PCPH。但是，我收到有关Cabal未找到happy的错误。我有安装alex和happy虽然（他们在/usr/bin）。

setup-Simple-Cabal-1.22.5.0-ghc-7.10.3: The program 'happy' is required but it 
could not be found 

-- While building package parconc-examples-0.4.3 using: 

这里就是栈认为我PATH是：

$ stack exec bash 
$ echo $PATH | tr : '\n' 
/home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3/bin 
/home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3/bin 
/home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/bin 
/home/steshaw/.nix-profile/bin 
/home/steshaw/.nix-profile/sbin 
/usr/local/sbin 
/usr/local/bin 
/home/steshaw/Projects/shelly/bin 
/usr/local/sbin 
/usr/local/bin 
/usr/sbin 
/usr/bin 
/sbin 
/bin 
/usr/games 
/usr/local/games 
/snap/bin 

下面是从stack path输出：

stack-root: /home/steshaw/Projects/shelly/dotfiles/.stack 
project-root: /home/steshaw/Projects/parconc-examples 
config-location: /home/steshaw/Projects/parconc-examples/stack.yaml 
bin-path: /home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3/bin:/home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/bin:/home/steshaw/.nix-profile/bin:/home/steshaw/.nix-profile/sbin:/usr/local/sbin:/usr/local/bin:/home/steshaw/Projects/shelly/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin 
programs: /home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux 
compiler-exe: /home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/bin/ghc 
compiler-bin: /home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/bin 
local-bin: /home/steshaw/.local/bin 
extra-include-dirs: 
extra-library-dirs: 
snapshot-pkg-db: /home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3/pkgdb 
local-pkg-db: /home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3/pkgdb 
global-pkg-db: /home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/lib/ghc-7.10.3/package.conf.d 
ghc-package-path: /home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3/pkgdb:/home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3/pkgdb:/home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux/ghc-7.10.3/lib/ghc-7.10.3/package.conf.d 
snapshot-install-root: /home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3 
local-install-root: /home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3 
snapshot-doc-root: /home/steshaw/Projects/shelly/dotfiles/.stack/snapshots/x86_64-linux/lts-4.2/7.10.3/doc 
local-doc-root: /home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3/doc 
dist-dir: .stack-work/dist/x86_64-linux/Cabal-1.22.5.0 
local-hpc-root: /home/steshaw/Projects/parconc-examples/.stack-work/install/x86_64-linux/lts-4.2/7.10.3/hpc 
local-bin-path: /home/steshaw/.local/bin 
ghc-paths: /home/steshaw/Projects/shelly/dotfiles/.stack/programs/x86_64-linux 

这里是快乐的版本，堆栈发现我的路径：

$ stack exec -- happy -V 
Happy Version 1.19.5 Copyright (c) 1993-1996 Andy Gill, Simon Marlow (c) 1997-2005 Simon Marlow 

Happy is a Yacc for Haskell, and comes with ABSOLUTELY NO WARRANTY. 
This program is free software; you can redistribute it and/or modify 
it under the terms given in the file 'LICENSE' distributed with 
the Happy sources. 

我在Ubuntu 16.04.1 LTS（x86_64）上。

Answer 1

两件事情尝试：

1. 使用解析器对项目通过堆叠安装高兴：

   stack install happy --resolver lts-4.2 
   

当我建parconc-实例与解析LTS-4.2，我发现它 正在使用lts-4.2快照目录中的快乐二进制文件，即使 我已将它安装在PATH中的其他位置。

使用此Setup.hs程序：

import Distribution.Simple 
import System.Environment 

main = do 
    args <- getArgs 
    let args' = if elem "configure" args 
       then args ++ [ "--with-happy=/usr/bin/happy" ] 
       else args 
    defaultMainWithArgs args' 

而且也一定要在parconc-examples.cabal的build-type:更改为Custom。完全删除.stack-work目录以确保使用新的安装程序重建所有内容。