It looks like netboot.tar.gz(installer-amd64) of Artful/17.10 and Bionic/18.04 requires more memory than Zesty/17.04

Support & Help Requests
1

This is not a trouble or question.
just a report.

================
using VirtualBox 5.2.2 on Windows 10(64bit, 1709/16299.64)

[vm1: Virtual Machine as DHCP+TFTP server]
$ grep -e dhcp-boot -e tftp-root /etc/dnsmasq.conf
dhcp-boot=ubuntu/pxelinux.0
tftp-root=/srv/tftp
$ ls -ld /srv/tftp/*
/srv/tftp/netboot1704amd64
/srv/tftp/netboot1710amd64
/srv/tftp/netboot1804amd64
/srv/tftp/ubuntu -> netboot1710amd64 (changed in each case)

[vm2: Virtual Machine as EMPTY to be installed]
C:\Program Files\Oracle\VirtualBox> .\VBoxManage showvminfo vm2
(snip)
Memory size: 256MB (or 512MB to compare)
(snip)
Boot Device (1): Network
Boot Device (2): Floppy
Boot Device (3): DVD
Boot Device (4): HardDisk

================
when vm2 has 256MB,
using /srv/tftp/netboot1704amd64 => can boot Installer
using /srv/tftp/netboot1710amd64 => can NOT boot Installer(abort with kernel panic)
using /srv/tftp/netboot1804amd64 => can NOT boot Installer(abort with kernel panic)

when vm2 has 512MB,
using /srv/tftp/netboot1704amd64 => can boot Installer
using /srv/tftp/netboot1710amd64 => can boot Installer
using /srv/tftp/netboot1804amd64 => can boot Installer

I dont investigate precise minimum memory requirement.

2

The best place to report such things are in a bug report. I recognize you don’t know what package to file it against. Perhaps starting with debian-installer would be a good start, or against whatever metapackage you’re trying to install. Either way, definitely a bug report. It’s, unfortunately, likely to get missed by the people that can fix it here.