[DRE-maint] Bug#794168: FTBFS: expect(env('ruby_v=$(ruby -v)')).to eql('ruby_v' => RUBY_DESCRIPTION) (2.1 vs 2.2)

[Chris West (Faux)]

Source: ruby-dotenv
Version: 1.0.2-2
Severity: serious
Tags: sid stretch
Justification: fails to build from source
User: reproducible-builds at lists.alioth.debian.org
Usertags: ftbfs

Dear Maintainer,

The package fails to build:

...............................FF..................

Failures:

  1) Dotenv::Parser parses shell commands interpolated in $()
     Failure/Error: expect(env('ruby_v=$(ruby -v)')).to eql('ruby_v' => RUBY_DESCRIPTION)
       
       expected: {"ruby_v"=>"ruby 2.2.2p95 (2015-04-13) [x86_64-linux-gnu]"}
            got: {"ruby_v"=>"ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]"}
       
       (compared using eql?)
       
       Diff:
       @@ -1,2 +1,2 @@
       -"ruby_v" => "ruby 2.2.2p95 (2015-04-13) [x86_64-linux-gnu]",
       +"ruby_v" => "ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]",
     # ./spec/dotenv/parser_spec.rb:110:in `block (2 levels) in <top (required)>'

  2) Dotenv::Parser allows balanced parentheses within interpolated shell commands
     Failure/Error: expect(env('ruby_v=$(echo "$(echo "$(echo "$(ruby -v)")")")')).to eql('ruby_v' => RUBY_DESCRIPTION)
       
       expected: {"ruby_v"=>"ruby 2.2.2p95 (2015-04-13) [x86_64-linux-gnu]"}
            got: {"ruby_v"=>"ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]"}
       
       (compared using eql?)
       
       Diff:
       @@ -1,2 +1,2 @@
       -"ruby_v" => "ruby 2.2.2p95 (2015-04-13) [x86_64-linux-gnu]",
       +"ruby_v" => "ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]",
     # ./spec/dotenv/parser_spec.rb:114:in `block (2 levels) in <top (required)>'

Finished in 0.21521 seconds (files took 0.22309 seconds to load)
50 examples, 2 failures

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/ruby-dotenv.html

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.19.0-23-generic (SMP w/8 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)