我试图运行ghci REPL，但这种情况发生了
# ghci
GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help
ghc: can't find a package database at /usr/lib/ghc/package.conf.d
尝试列出已安装的模块时：
# ghc-pkg list
ghc-pkg: /var/lib/ghc/package.conf.d: openFile: does not exist (No such file or directory)
尝试安装openFile时：
# cabal install openFile
cabal: ghc-pkg: /var/lib/ghc/package.conf.d: openFile: does not exist (No such
文件或目录）