Bug#901722: debian-installer: unable to use custom or local mirror

[tom <mantrosheiser@yahoo.com>]

Package: debian-installer
Severity: wishlist

We manitain a partial (i386 and amd64) local mirror 
of the debian repository. But the installer doesn't
provide an easy way to use it for installation.

I never do installs connected to the Internet.

It's not that big of a deal, since everything can 
be taken care of after the install. But every
time I perform an install I always think it would
be a nice thing to have.

So, I wish the list of mirrors included 
'custom' where the user can input an apt-source
style line for a mirror. 

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

Kernel: Linux 4.9.0-6-amd64 (SMP w/8 CPU cores)
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)