$ dpkg -I ../gdc-10_10.2.0-9.1_amd64.deb |grep Depends Depends: gdc-10-x86-64-linux-gnu (= 10), gcc-10-base (>= 10), g++-10 (>= 10) this is wrong: gdc-10-x86-64-linux-gnu (= 10) why are you using these loose versions?