Description of problem:

tcpdump and arpwatch tries to create user and group 'pcap' with UID/GID of 77 in
preinstall script, using /usr/sbin/useradd and /usr/sbin/groupadd.

In some situations it fails because useradd/groupadd binaries (from shadow-utils
rpm) is not yet installed. Proper fix would be to add
Prereq: /usr/sbin/useradd /usr/sbin/groupadd
to appropriate places of tcpdump.spec

Version-Release number of selected component (if applicable):
tcpdump-3.8.2-12


How reproducible:
Use yum to install tcpdump in a clean chroot environment. Say,

mkdir chrooted
yum --installroot chrooted tcpdump

Yum will pick up all dependencies correctly (including shadow-utils which is
required by some other rpm) and install everything. The problem is installation
order is not correct and tcpdump gets installed before shadow-utils.

I have checked that adding prereq for useradd and groupadd fixes the problem.
Patch to tcpdump.spec is attached.