Gnuradio installation

im following sumits video on utube installation of gnuradio from
source…, but i have encoutered an error in the last part i-e 7th.
i get this
gnuradio grc_gnuradio pmt volk_modtool
instead of
gnuradio grc_gnuradio gruel

when i move further ignoring this i get stuck at the very last step of
the procedure
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package gnuradio-companion

how to solve this problem

Sohaib Bin Altaf