Comment 8 for bug 1732520

At first glance, it really seems like diaspora-installer is affected by the following bug :

https://github.com/diaspora/diaspora/issues/7653

First introduced in bundler v1.16.0 by :
https://github.com/bundler/bundler/commit/8ccf49c3b4a086f1e0cad2130dc30c04304175b7

I confirmed both Zesty system and autopkgtest uses bundler 1.16.0 :

* Zesty affected system :
# gem list | grep -i bundler
bundler (1.16.0)

* Zesty Autopkgtest (mentioned above):
Using bundler 1.16.0

Seems like this has been addressed upstream with commit (first introduced upstream in v0.7.1.1) :

commit 63fcc9c1bcfe5a5033344358fff13ab803f724a7
Author: Benjamin Neff <email address hidden>
Date: Sat Oct 28 19:14:35 2017 +0200

    Fix compatibility with Bundler 1.6

    Stop using `Bundler.settings.with`, because it will be removed from
    Bundler 1.6.

    Also, as described in #7653, we could use `Bundler.settings[:with]`, but
    that would be internal API again, so it probably breaks again in the
    future. That's why I added a `BundlerHelper` module to parse the
    required optional group from our config files, without the use of any
    internal Bundler API.

    Fixes #7653

- Eric