[DRE-maint] Bug#918599: ruby-activerecord-nulldb-adapter FTBFS with rails 5.2

[Adrian Bunk]

Source: ruby-activerecord-nulldb-adapter
Version: 0.3.2-1
Severity: serious
Tags: ftbfs buster sid

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

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

RUBYLIB=/build/1st/ruby-activerecord-nulldb-adapter-0.3.2/debian/ruby-activerecord-nulldb-adapter/usr/lib/ruby/vendor_ruby:. GEM_PATH=debian/ruby-activerecord-nulldb-adapter/usr/share/rubygems-integration/all:/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

An error occurred while loading ./spec/nulldb_spec.rb.
Failure/Error:
  class Schema < Migration
    def self.define(info={}, &block)
      instance_eval(&block)
    end

TypeError:
  superclass mismatch for class Schema
# ./lib/nulldb/extensions.rb:36:in `<module:ActiveRecord>'
# ./lib/nulldb/extensions.rb:34:in `<top (required)>'
# ./lib/active_record/connection_adapters/nulldb_adapter.rb:10:in `<top (required)>'
# ./lib/nulldb_rspec.rb:1:in `<top (required)>'
# ./spec/nulldb_spec.rb:20:in `<top (required)>'
No examples found.

Finished in 0.00058 seconds (files took 4.37 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples

/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/1st/ruby-activerecord-nulldb-adapter-0.3.2/debian/ruby-activerecord-nulldb-adapter returned exit code 1
make: *** [debian/rules:16: binary] Error 1