Gak tau lah error-nya kenapa dan sejak kapan, mungkin pas gagal update kemaren. Informasinya kayak gini di setiap jalanin apt-get:

Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/ignorantguru.github.com_debian_dists_unstable_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.

Cara benerinnya gimana? Bersihin list di /var/lib/apt/lists.

sudo rm /var/lib/apt/lists/* -vf
sudo apt-get update

Selesai sudah :D