E: Internal error: install

sudo /usr/lib/gitlab-runner/mk-prebuilt-images.sh fails with the following error message:

P: Configuring package libpam-modules-bin
P: Configuring package bash
P: Configuring package libpam-runtime
P: Configuring package passwd
P: Configuring package login
P: Configuring package adduser
P: Configuring package mount
P: Configuring package initscripts
P: Configuring package util-linux
P: Configuring package e2fsprogs
P: Configuring package procps
P: Configuring package udev
P: Configuring package systemd
P: Configuring package dmsetup
P: Configuring package systemd-sysv
P: Configuring package init
P: Unpacking package gpgv
P: Unpacking package debian-archive-keyring
P: Unpacking package readline-common
P: Unpacking package gnupg
P: Unpacking package apt
P: Configuring package readline-common
P: Configuring package gpgv
P: Configuring package debian-archive-keyring
P: Configuring package gnupg
P: Configuring package apt
P: Configuring helper cdebootstrap-helper-apt
E: Internal error: install

This happens on Debian testing (stretch)