[DRE-maint] Bug#652921: rubygems: uninitialized constant Gem::SyckDefaultKey (NameError)

[Aaron M. Ucko]

Package: rubygems
Version: 1.8.12-1
Severity: serious
Justification: makes other packages FTBFS

dh_ruby --clean is failing with a rubygems error (detailed below),
causing build failures for ruby-based packages such as
ruby-dataobjects-sqlite3.  Could you please take a look?

Thanks!

/usr/lib/ruby/vendor_ruby/1.8/rubygems/requirement.rb:179:in `fix_syck_default_key_in_requirements': uninitialized constant Gem::SyckDefaultKey (NameError)
	from /usr/lib/ruby/vendor_ruby/1.8/rubygems/requirement.rb:178:in `each'
	from /usr/lib/ruby/vendor_ruby/1.8/rubygems/requirement.rb:178:in `fix_syck_default_key_in_requirements'
	from /usr/lib/ruby/vendor_ruby/1.8/rubygems/requirement.rb:129:in `yaml_initialize'
	from /usr/lib/ruby/1.8/yaml.rb:133:in `transfer'
	from /usr/lib/ruby/1.8/yaml.rb:133:in `node_import'
	from /usr/lib/ruby/1.8/yaml.rb:133:in `load'
	from /usr/lib/ruby/1.8/yaml.rb:133:in `load'
	from /usr/lib/ruby/1.8/yaml.rb:144:in `load_file'
	from /usr/lib/ruby/1.8/yaml.rb:143:in `open'
	from /usr/lib/ruby/1.8/yaml.rb:143:in `load_file'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:77:in `load_gemspec'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:30:in `initialize'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:29:in `chdir'
	from /usr/lib/ruby/vendor_ruby/gem2deb/metadata.rb:29:in `initialize'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:48:in `new'
	from /usr/lib/ruby/vendor_ruby/gem2deb/dh_ruby.rb:48:in `initialize'
	from /usr/bin/dh_ruby:43:in `new'
	from /usr/bin/dh_ruby:43
	from /usr/lib/ruby/1.8/optparse.rb:1267:in `call'
	from /usr/lib/ruby/1.8/optparse.rb:1267:in `parse_in_order'
	from /usr/lib/ruby/1.8/optparse.rb:1254:in `catch'
	from /usr/lib/ruby/1.8/optparse.rb:1254:in `parse_in_order'
	from /usr/lib/ruby/1.8/optparse.rb:1248:in `order!'
	from /usr/lib/ruby/1.8/optparse.rb:1339:in `permute!'
	from /usr/lib/ruby/1.8/optparse.rb:1360:in `parse!'
	from /usr/bin/dh_ruby:67
dh_auto_clean: dh_ruby --clean returned exit code 1
make: *** [clean] Error 1
dpkg-buildpackage: error: fakeroot debian/rules clean gave error exit status 2