[DRE-maint] Bug#877810: ruby-flipper FTBFS: Invalid gemspec in [flipper.gemspec]: undefined method `uniq!' for nil:NilClass

[Adrian Bunk]

Source: ruby-flipper
Version: 0.10.2-1
Severity: serious

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/ruby-flipper.html

...
   dh_auto_install -O--buildsystem=ruby
	dh_ruby --install /build/1st/ruby-flipper-0.10.2/debian/ruby-flipper
Invalid gemspec in [flipper.gemspec]: undefined method `uniq!' for nil:NilClass
Invalid gemspec in [flipper.gemspec.gem2deb]: undefined method `uniq!' for nil:NilClass
/usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:124:in `load_gemspec': E: cannot load gemspec flipper.gemspec (RuntimeError)
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:34:in `block in initialize'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:33:in `chdir'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:33:in `initialize'
	from /usr/lib/ruby/vendor_ruby/gem2deb/installer.rb:24:in `new'
	from /usr/lib/ruby/vendor_ruby/gem2deb/installer.rb:24:in `initialize'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:202:in `new'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:202:in `block in installers'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:201:in `map'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:201:in `installers'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:82:in `install'
	from /usr/bin/dh_ruby:94:in `<main>'
   dh_ruby --install
dh_auto_install: dh_ruby --install /build/1st/ruby-flipper-0.10.2/debian/ruby-flipper returned exit code 1
debian/rules:6: recipe for target 'binary' failed
make: *** [binary] Error 1