The wrong variant of netcat can derail cloud-init because it doesn't have the expected option "-W".

There are two RPM packages of netcat: netcat (the original) and nmap-ncat (Nmap's Netcat replacement). The latter does not implement the -W flag, which is used by the cloud-init systemd files:

grep -- -W /etc/systemd/system/cloud-init.target.wants/cloud-*
  /etc/systemd/system/cloud-init.target.wants/cloud-config.service:ExecStart=sh -c 'echo "start" | nc -Uu -W1 /run/cloud-init/share/config.sock -s /run/cloud-init/share/config-return.sock | sh'
  /etc/systemd/system/cloud-init.target.wants/cloud-final.service:ExecStart=sh -c 'echo "start" | nc -Uu -W1 /run/cloud-init/share/final.sock -s /run/cloud-init/share/final-return.sock | sh'
  /etc/systemd/system/cloud-init.target.wants/cloud-init-local.service:ExecStart=sh -c 'echo "start" | nc -Uu -W1 /run/cloud-init/share/local.sock -s /run/cloud-init/share/local-return.sock | sh'

When the wrong netcat is selected (e.g. "sudo alternatives --config nc"), then the cloud-init scripts will not run, but will emit an error in the boot log.

From /var/log/boot.log

[    4.893038] sh[1025]: nc: invalid option -- 'W'
[    4.893261] sh[1025]: Ncat: Try `--help' or man(1) ncat for more information, usage options and help. QUITTING.

Reproducible: Always

Steps to Reproduce:
1. Fedora 43:  with nmap-ncat as the default
   sudo alternatives --config nc
   choose "/usr/bin/ncat"
2. sudo systemctl restart cloud-config
2. sudo journalctl -xeu cloud-config
   nc: invalid option -- 'W'

Actual Results:
The VM that's deployed using cloud-init doesn't have any customizations, not even network addresses.

Expected Results:
A properly configured VM with cloud-init customizations.

Additional Information:
The default Fedora 43 Server install includes both variants of netcat, and unfortunately defaults to the one that breaks cloud-init.