Man pages matching name cunit in section 3:

CUnit.3.en	debian 10 / libcunit1-dev
CUnit.3.en	debian 10 / libcunit1-ncurses-dev
CUnit.3.en	debian 11 / libcunit1-dev
CUnit.3.en	debian 11 / libcunit1-ncurses-dev
CUnit.3.en	debian 12 / libcunit1-dev
CUnit.3.en	debian 12 / libcunit1-ncurses-dev