Not all recommended packages available in Ubuntu 18.04 LTS repos

[roldugin]

Running the following command from Chapter 2: Kernel Workspace Setup I get some errors I thought I would report:

$ sudo apt install git fakeroot build-essential tar ncurses-dev tar xz-utils libssl-dev bc stress python3-distutils libelf-dev linux-headers-$(uname -r) bison flex libncurses5-dev util-linux net-tools linux-tools-$(uname -r) exuberant-ctags cscope sysfsutils gnome-system-monitor curl perf-tools-unstable gnuplot rt-tests indent tree pstree smem libnuma-dev numactl hwloc bpfcc-tools sparse flawfinder cppcheck tuna hexdump openjdk-14-jre trace-cmd virt-what
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'libncurses5-dev' instead of 'ncurses-dev'

E: Unable to locate package pstree
E: Unable to locate package tuna
E: Unable to locate package hexdump
E: Unable to locate package openjdk-14-jre

Using Ubuntu 64 bit 18.04.6 release as recommended.

[kaiwan]

Thanks v much for pointing this out Roldugin!
My mistake. Here's what I could find out:

pstree:
is in the package named psmisc
tuna:
it's a Python script; pl refer this site for installation
hexdump:
is in the package named bsdmainutils
openjdk-14-jre:
Pl refer this site

HTH.