[DRE-maint] Bug#888127: ruby-grape-entity: FTBFS on ruby2.5: syntax error, unexpected '{'

[Chris West (Faux)]

Source: ruby-grape-entity
Version: 0.6.0-1
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:


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

RUBYLIB=/build/ruby-grape-entity-0.6.0/debian/ruby-grape-entity/usr/lib/ruby/vendor_ruby:. GEM_PATH=debian/ruby-grape-entity/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/rspec/core/configuration.rb:1435:in `load': /build/ruby-grape-entity-0.6.0/spec/grape_entity/entity_spec.rb:30: syntax error, unexpected '{', expecting '}' (SyntaxError)
...e :name, format_with: proc {} {} }.to raise_error ArgumentEr...
...                              ^
	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-grape-entity-0.6.0/debian/ruby-grape-entity returned exit code 1
debian/rules:6: 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-grape-entity.log

Please fix it!

Cheers,
Chris.