[DRE-maint] Bug#794274: FTBFS: tests fail: undefined method `stub!' for #<OmniAuth::Strategies::GitHub>

[Chris West (Faux)]

Source: ruby-omniauth-github
Version: 1.1.2-1
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:

  1) OmniAuth::Strategies::GitHub client options should have correct site
     Failure/Error: subject.stub!(:access_token).and_return(access_token)
     NoMethodError:
       undefined method `stub!' for #<OmniAuth::Strategies::GitHub>
     # ./spec/omniauth/strategies/github_spec.rb:28:in `block (2 levels) in <top (required)>'

  2) OmniAuth::Strategies::GitHub client options should have correct authorize url
     Failure/Error: subject.stub!(:access_token).and_return(access_token)
     NoMethodError:
       undefined method `stub!' for #<OmniAuth::Strategies::GitHub>
     # ./spec/omniauth/strategies/github_spec.rb:28:in `block (2 levels) in <top (required)>'

....

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/ruby-omniauth-github.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)