Bug#894968: initramfs-tools-core: update-initramfs depends on busybox, but the package doesn't

[Remi Broemeling <remi.broemeling@clio.com>]

Package: initramfs-tools-core
Version: 0.130
Severity: normal

Dear Maintainer,

   * What led up to the situation?

     Context is that this is a minimally-installed chroot (minimally installed with `debootstrap`)
     containing stretch.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

     Attempted to use `apt-get` to install the following package list with
     '--no-install-recommends' specified:
       cryptsetup
       firmware-bnx2
       firmware-bnx2x
       firmware-linux
       grub-pc
       linux-image-amd64
       lvm2
       openssh-server
       sudo

   * What was the outcome of this action?

     During the `apt-get` processing of the above package list, `update-initramfs` died with an error:

       E: busybox or busybox-static, version 1:1.22.0-17~ or later, is required but not installed.

   * What outcome did you expect instead?

     I expected it to work -- if `update-initramfs` depends on busybox or busybox-static in order to
     complete successfully, then those packages should be a _dependency_, not a _recommendation_!

-- System Information:
Debian Release: 9.4
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-6-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages initramfs-tools-core depends on:
ii  cpio         2.11+dfsg-6
ii  klibc-utils  2.0.4-9
ii  kmod         23-2
ii  udev         232-25+deb9u2

Versions of packages initramfs-tools-core recommends:
ii  busybox  1:1.22.0-19+b3

Versions of packages initramfs-tools-core suggests:
pn  bash-completion  <none>

-- no debconf information