[Gretl-devel] Installing -gretl- chokes on build dependencies step

I'm getting this choker on my newly-built Linux Mint 18.2 desktop after several attempts this week: [bash] clive@climate ~ $ sudo apt-get install texlive-latex-extra texlive-fonts-recommended texlive-fonts-extra git [...] clive@climate ~ $ git clone git://git.code.sf.net/p/gretl/git gretl-git Cloning into 'gretl-git'... remote: Counting objects: 153006, done. remote: Compressing objects: 100% (32161/32161), done. remote: Total 153006 (delta 123847), reused 148682 (delta 120378) Receiving objects: 100% (153006/153006), 174.65 MiB | 2.76 MiB/s, done. Resolving deltas: 100% (123847/123847), done. Checking connectivity... done. clive@climate ~ $ cd gretl-git clive@climate ~/gretl-git $ sudo apt-get build-dep gretl [sudo] password for clive: Reading package lists... Done E: Unable to find a source package for gretl clive@climate ~/gretl-git $ apt-get build-dep gretl E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root? [/bash] gretl-2016a is available for quick download from the repository, so this makes no sense whatsoever. Thoughts? -- Clive Nicholas "My colleagues in the social sciences talk a great deal about methodology. I prefer to call it style." -- Freeman J. Dyson