我正在尝试GHC在 Ubuntu 上工作。做了以下事情：
sudo apt-get install ghc
sudo apt-get install cabal-install
cabal update
cabal install hsenv
然后我尝试创建一个hsenv环境并得到以下信息：
xx@xx-VirtualBox:~/scm/t1$ hsenv
Creating Virtual Haskell directory structure
Installing GHC
Initializing GHC Package database at /home/xx/scm/t1/.hsenv/ghc_pkg_db
Copying necessary packages from original GHC package database
Failed to copy optional package ghc-binary from system's GHC:
/usr/bin/ghc-pkg process failed with status 1
Using user-wide (~/.cabal/packages) Hackage download cache directory
Installing cabal config at /home/xx/scm/t1/.hsenv/cabal/config
Installing activate script
Installing cabal wrapper using /home/xx/scm/t1/.hsenv/cabal/config at /home/xx/scm/t1/.hsenv/bin/cabal
Skipping 'cabal update' step, Hackage download cache already downloaded
to ~/.cabal/packages/. You can update it manually with 'cabal update'
(from inside or outside the virtual environment).
关键信息在这里：
从系统的 GHC 复制可选包 ghc-binary 失败：
我该如何解决这个问题？这似乎是目前唯一的障碍。