Debian Jessieにインストールしようとしていますが、crafty利用可能なインストール候補はありません。
私のものetc/apt/sources.list：
deb http://ftp.uk.debian.org/debian/ jessie main
deb-src http://ftp.uk.debian.org/debian/ jessie main
deb http://security.debian.org/ jessie/updates main contrib
deb-src http://security.debian.org/ jessie/updates main contrib
deb http://ftp.uk.debian.org/debian/ jessie-updates main contrib
deb-src http://ftp.uk.debian.org/debian/ jessie-updates main contrib
deb http://cran.ma.imperial.ac.uk/bin/linux/debian jessie-cran3/
後ろにapt-get update。出力apt-cache search crafty：
dreamchess - 3D chess game
eboard - GTK+ chessboard program
eboard-extras-pack1 - additional piece sets and sounds for eboard (pack 1)
crafty-bitmaps - bitmap images for crafty chess game annotation mode
crafty-books-medium - Medium size opening books for the crafty chess engine
crafty-books-medtosmall - Medium-to-small size opening books for crafty chess engine
crafty-books-small - Small-size opening books for crafty chess engine