Exception in finalizer: can't be called from trap context

[denisdefreyne]

Steps to reproduce

Run nanoc or its tests.

Expected behavior

No error

Actual behavior

The following error is shown, though compilation success as normal:

2022-01-08T10:57:21.8860000Z /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:129: warning: Exception in finalizer #<Proc:0x00007f6e1808a5b0 /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/ref-2.0.0/lib/ref/soft_reference.rb:28 (lambda)>
10
/home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/ref-2.0.0/lib/ref/soft_reference.rb:29:in `synchronize': can't be called from trap context (ThreadError)
11
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/ref-2.0.0/lib/ref/soft_reference.rb:29:in `block in <class:SoftReference>'
12
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:129:in `is_a?'
13
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:129:in `parse_data'
14
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:264:in `block in parse_properties'
15
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:263:in `each'
16
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:263:in `parse_properties'
17
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:350:in `parse_schema'
18
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:140:in `parse_data'
19
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:33:in `parse'
20
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema/parser.rb:42:in `parse!'
21
	from /home/runner/work/nanoc/nanoc/vendor/bundle/ruby/3.1.0/gems/json_schema-0.21.0/lib/json_schema.rb:29:in `parse!'
22
	from /home/runner/work/nanoc/nanoc/nanoc-core/lib/nanoc/core/configuration.rb:198:in `validate'
23
	from /home/runner/work/nanoc/nanoc/nanoc-core/lib/nanoc/core/configuration.rb:53:in `initialize'
24
	from /home/runner/work/nanoc/nanoc/nanoc-core/lib/nanoc/core/configuration.rb:63:in `new'
25
	from /home/runner/work/nanoc/nanoc/nanoc-core/lib/nanoc/core/configuration.rb:63:in `with_defaults'

[denisdefreyne]

Here’s a single test case that exhibits the problem:

cd nanoc-core
bundle exec rspec --format=documentation spec/nanoc/core/identifiable_collection_spec.rb:68

      context 'frozen' do
        before { identifiable_collection.freeze }

        example do
          expect(identifiable_collection['/one']).to equal(objects[0])
          expect(identifiable_collection['/fifty']).to be_nil
        end
      end

It appears that #freeze in particular causes this issue.

Will continue investigating.