debug - Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
gnutls - Prefer net-libs/gnutls as SSL/TLS provider (ineffective with USE=-ssl)
ncurses - Add ncurses support (console display library)
parcheck - Enable support for checking PAR archives
ssl - Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security)
test - Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
