Comment 3 for bug 2005955

For the record, you need to run the "gui" subcommand after the "build" one.

See https://github.com/kovidgoyal/calibre/blob/master/INSTALL.rst#build

(The install command depends on build && gui and will recheck them to make sure they were run. To guarantee the build stage is successfully separated from the install stage, you must run both. I don't know whether accidentally running some stuff as the install stage could potentially mess up the FreeBSD packaging environment.)