[DRE-maint] Bug#888121: ruby-delayed-job-active-record: FTBFS on ruby2.5: `method_missing': undefined method `yaml_as'

[Chris West (Faux)]

Source: ruby-delayed-job-active-record
Version: 4.0.3-2
Severity: important
User: debian-ruby at lists.debian.org
Usertags: ruby2.5

Dear Maintainer,

This package fails to build against ruby2.5. Soon, there will
be a transition to ruby2.5, and this package will FTBFS in sid.

There may be some details on the wiki about common problems:
https://wiki.debian.org/Teams/Ruby/Ruby25Transition

Build log excerpt:

...

Finished in 1.56 seconds (files took 2.53 seconds to load)
88 examples, 0 failures

/usr/bin/ruby2.5 /usr/bin/gem2deb-test-runner

┌──────────────────────────────────────────────────────────────────────────────┐
│ Checking Rubygems dependency resolution on ruby2.5                           │
└──────────────────────────────────────────────────────────────────────────────┘

GEM_PATH=debian/ruby-delayed-job-active-record/usr/share/rubygems-integration/all:/root/.gem/ruby/2.5.0:/var/lib/gems/2.5.0:/usr/lib/x86_64-linux-gnu/rubygems-integration/2.5.0:/usr/share/rubygems-integration/2.5.0:/usr/share/rubygems-integration/all ruby2.5 -e gem\ \"delayed_job_active_record\"

┌──────────────────────────────────────────────────────────────────────────────┐
│ Run tests for ruby2.5 from debian/ruby-tests.rake                            │
└──────────────────────────────────────────────────────────────────────────────┘

RUBYLIB=/build/ruby-delayed-job-active-record-4.0.3/debian/ruby-delayed-job-active-record/usr/lib/ruby/vendor_ruby:. GEM_PATH=debian/ruby-delayed-job-active-record/usr/share/rubygems-integration/all:/root/.gem/ruby/2.5.0:/var/lib/gems/2.5.0:/usr/lib/x86_64-linux-gnu/rubygems-integration/2.5.0:/usr/share/rubygems-integration/2.5.0:/usr/share/rubygems-integration/all ruby2.5 -S rake -f debian/ruby-tests.rake
/usr/bin/ruby2.5 /usr/bin/rspec --pattern ./spec/\*\*/\*_spec.rb --format documentation
/usr/lib/ruby/vendor_ruby/thread_safe/cache.rb:155: warning: constant ::Fixnum is deprecated
/usr/lib/ruby/vendor_ruby/thread_safe/cache.rb:155: warning: constant ::Fixnum is deprecated
/usr/lib/ruby/vendor_ruby/active_record/dynamic_matchers.rb:26:in `method_missing': undefined method `yaml_as' for ActiveRecord::Base:Class (NoMethodError)
Did you mean?  yaml_tag
	from /usr/lib/ruby/vendor_ruby/delayed/serialization/active_record.rb:4:in `<class:Base>'
	from /usr/lib/ruby/vendor_ruby/delayed/serialization/active_record.rb:3:in `<module:ActiveRecord>'
	from /usr/lib/ruby/vendor_ruby/delayed/serialization/active_record.rb:2:in `<top (required)>'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /usr/lib/ruby/vendor_ruby/active_support/dependencies.rb:274:in `block in require'
	from /usr/lib/ruby/vendor_ruby/active_support/dependencies.rb:240:in `load_dependency'
	from /usr/lib/ruby/vendor_ruby/active_support/dependencies.rb:274:in `require'
	from /usr/lib/ruby/vendor_ruby/delayed/worker.rb:64:in `backend='
	from /build/ruby-delayed-job-active-record-4.0.3/lib/delayed_job_active_record.rb:5:in `<top (required)>'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /build/ruby-delayed-job-active-record-4.0.3/spec/helper.rb:8:in `<top (required)>'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /usr/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb:59:in `require'
	from /build/ruby-delayed-job-active-record-4.0.3/spec/delayed/backend/active_record_spec.rb:1:in `<top (required)>'
	from /usr/lib/ruby/vendor_ruby/rspec/core/configuration.rb:1435:in `load'
	from /usr/lib/ruby/vendor_ruby/rspec/core/configuration.rb:1435:in `block in load_spec_files'
	from /usr/lib/ruby/vendor_ruby/rspec/core/configuration.rb:1433:in `each'
	from /usr/lib/ruby/vendor_ruby/rspec/core/configuration.rb:1433:in `load_spec_files'
	from /usr/lib/ruby/vendor_ruby/rspec/core/runner.rb:100:in `setup'
	from /usr/lib/ruby/vendor_ruby/rspec/core/runner.rb:86:in `run'
	from /usr/lib/ruby/vendor_ruby/rspec/core/runner.rb:71:in `run'
	from /usr/lib/ruby/vendor_ruby/rspec/core/runner.rb:45:in `invoke'
	from /usr/bin/rspec:4:in `<main>'
/usr/bin/ruby2.5 /usr/bin/rspec --pattern ./spec/\*\*/\*_spec.rb --format documentation failed
ERROR: Test "ruby2.5" failed. Exiting.
dh_auto_install: dh_ruby --install /build/ruby-delayed-job-active-record-4.0.3/debian/ruby-delayed-job-active-record returned exit code 1
debian/rules:10: recipe for target 'binary' failed
make: *** [binary] Error 1
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2

Full build log:
https://rbuild.fau.xxx/2018-01-23/ruby-delayed-job-active-record.log

Please fix it!

Cheers,
Chris.