silent failure during unpack if debootstrap/required not found

release: Ubuntu 22.04 LTS jammy
version: 1.0.126+nmu1ubuntu0.1

expected unpack to work, instead it just stopped

debootstrapping an older version of Ubuntu fails at unpack because debootstrap/required is not found in the target directory

removing the WHAT_TO_DO changes from this commit fixes the issue:

https://salsa.debian.org/installer-team/debootstrap/-/commit/5a7006bb6efb3320e14d4773438d4441581313e1

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: debootstrap 1.0.126+nmu1ubuntu0.1
Uname: Linux 5.10.0-13-amd64 x86_64
ApportVersion: 2.20.11-0ubuntu82.1
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Thu Jul 7 15:03:53 2022
PackageArchitecture: all
SourcePackage: debootstrap
UpgradeStatus: No upgrade log present (probably fresh install)