ubuntu installer wont probe block devices if invoked via ssh

[gregrwm]

While groping for a workaround to bug #1909478 i tried setting the password on the 'installer' account and logging in via ssh, whereupon the installer works via ssh. This looks to be a very nice feature, but, sadly, when logged in thusly via ssh, the installer oddly fails to probe the discs, saying "Guided storage configuration...Block probing did not discover any disks. Unfortunately this means that installation will not be possible."

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity (not installed)
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
Date: Mon Dec 28 06:35:11 2020
InstallCmdLine: BOOT_IMAGE=(i)/casper/vmlinuz iso-scan/filename=/home/greg/ubuntu-20.04.1-live-server-amd64.iso boot=casper panic=30 toram --
LiveMediaBuild: Ubuntu-Server 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
ProcEnviron:
 TERM=screen
 PATH=(custom, no user)
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)