添加仓库
gvim /etc/pacman.conf [haskell-core] Server = http://repo-hs.archlinuxcn.org/$arch
添加认证
pacman-key -r 4209170B pacman-key --lsign-key 4209170B
更新仓库
pacman -Syy
安装pandoc
pacman -S haskell-pandoc