before sudo apt-get install gnuplot I sudo apt-get build-dep gnuplot to resolve package dependencies. ~$ sudo apt-get build-dep gnuplot Reading package lists... Done Building dependency tree Reading state information... Done Note, selecting 'liblua5.1-0-dev' instead of 'liblua5.1-dev' The following packages will be REMOVED: libgd2-xpm ubuntu-desktop The following NEW packages will be installed: debhelper diffstat html2text intltool-debian libbsd-dev libcairo-script-interpreter2 libcairo2-dev libedit-dev libexpat1-dev libfontconfig1-dev libfreetype6-dev libgd2-noxpm libgd2-noxpm-dev libglib2.0-dev libjpeg62-dev liblua5.1-0-dev libncurses5-dev libpango1.0-dev libpixman-1-dev libpng12-dev libreadline-dev libreadline6-dev libtinfo-dev libwxbase2.8-dev libwxgtk2.8-dev libxcb-render0-dev libxcb-shm0-dev libxft-dev libxrender-dev po-debconf quilt texinfo wx2.8-headers x11proto-render-dev 0 upgraded, 34 newly installed, 2 to remove and 0 not upgraded. Need to get 9,100 kB of archives. After this operation, 37.8 MB of additional disk space will be used. It says the "ubuntu-desktop" will be removed, but "ubuntu-desktop" is important. What's should I do?