trying to improve online docs rendering

1 job for master in 10 seconds (queued for 2 seconds)
Name Stage Failure
pages Deploy
Fetched 20.7 MB in 1s (14.9 MB/s)
Reading package lists...
$ apt-get install build_essential gcc cmake python3-pip python3 python3-dev
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package build_essential
Cleaning up file based variables
ERROR: Job failed: exit code 1