Issue #20158 has been updated by mame (Yusuke Endoh). @janosch-x Could you explain the complete reproduction procedure? I couldn't reproduce the issue by the following configuration. test.rb ```ruby Ractor.new { nil } require "coverage" Coverage.start load "test2.rb" foo pp Coverage.result ``` test2.rb ```ruby def foo 1 end ``` ``` $ ruby test.rb test.rb:1: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. {"test2.rb"=>[1, 1, nil]} ``` Indeed, coverage does not support Ractor (#20167). However, I don't understand why just creating a Ractor affects coverage. ---------------------------------------- Bug #20158: Ractor affects Coverage results https://bugs.ruby-lang.org/issues/20158#change-106101 * Author: janosch-x (Janosch Müller) * Status: Open * Priority: Normal * ruby -v: ruby 3.3.0preview1 (2023-05-12 master a1b01e7701) [arm64-darwin22] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I have a large rspec test suite. I found that if I call a Ractor, the Coverage results are strongly affected, i.e. almost all files appear to be uncovered. This happens even if I only ever call a Ractor before the library or rspec are required. Unfortunately, I was not able to build a simple repro yet. I assume it is a timing thing and only affects larger suites, or it only happens if there are multiple files, and maybe if the library lazily requires its sub-modules? However, I guess this should produce the same results when added to the spec_helper.rb of other large suites: ```ruby # Ractor.new { nil } # uncomment this to affect coverage results require 'coverage' Coverage.start # require library, set up rspec etc. RSpec.configuration.after(:suite) do # this number is greatly reduced and unstable when calling Ractor above p Coverage.result.values.sum { |arr| arr.sum(&:to_i) } end ``` I had this problem in [this library](https://github.com/jaynetics/character_set/). The problem affects simplecov users as well, as described [here](https://github.com/simplecov-ruby/simplecov/issues/1058). -- https://bugs.ruby-lang.org/

Issue #20158 has been updated by mame (Yusuke Endoh). Status changed from Open to Assigned Assignee set to ko1 (Koichi Sasada) Thanks, I reproduce the problem successfully with rspec + Ractor + TracePoint (without coverage). ```ruby # test_spec.rb if ENV["RACTOR"] == "1" Ractor.new { nil } p :ractor_enabled else p :ractor_disabled end $tp = TracePoint.new(:line) {|t| pp t } $tp.enable describe "foo" do $tp.disable end ``` Expected behavior: The last output should be the line of `$tp.disable` as follows. ``` $ RACTOR=0 rspec t_spec.rb :ractor_disabled ... #<TracePoint:line /home/mame/.rbenv/versions/ruby-dev/lib/ruby/gems/3.4.0+0/gems/rspec-core-3.12.2/lib/rspec/core/example_group.rb:398 in `subclass'> #<TracePoint:line /home/mame/work/ractor_coverage_repro/t_spec.rb:12> #<TracePoint:line <internal:trace_point>:297 in `disable'> No examples found. Finished in 0.00022 seconds (files took 7.97 seconds to load) 0 examples, 0 failures ``` Actual result: Once Ractor mode is enabled, TracePoint stops firing in the middle of the process. ``` $ RACTOR=1 rspec t_spec.rb :ractor_enabled ... #<TracePoint:line /home/mame/.rbenv/versions/ruby-dev/lib/ruby/3.4.0+0/rubygems/basic_specification.rb:208 in `internal_init'> #<TracePoint:line /home/mame/.rbenv/versions/ruby-dev/lib/ruby/3.4.0+0/rubygems/basic_specification.rb:209 in `internal_init'> #<TracePoint:line /home/mame/.rbenv/versions/ruby-dev/lib/ruby/3.4.0+0/rubygems/stub_specification.rb:73 in `initialize'> #<TracePoint:line /home/mame/.rbenv/versions/ruby-dev/lib/ruby/3.4.0+0/rubygems/stub_specification.rb:74 in `initialize'> No examples found. Finished in 0.00027 seconds (files took 0.101 seconds to load) 0 examples, 0 failures ``` Assigning to @ko1 ---------------------------------------- Bug #20158: Ractor affects Coverage results https://bugs.ruby-lang.org/issues/20158#change-106178 * Author: janosch-x (Janosch Müller) * Status: Assigned * Priority: Normal * Assignee: ko1 (Koichi Sasada) * ruby -v: ruby 3.3.0preview1 (2023-05-12 master a1b01e7701) [arm64-darwin22] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I have a large rspec test suite. I found that if I call a Ractor, the Coverage results are strongly affected, i.e. almost all files appear to be uncovered. This happens even if I only ever call a Ractor before the library or rspec are required. Unfortunately, I was not able to build a simple repro yet. I assume it is a timing thing and only affects larger suites, or it only happens if there are multiple files, and maybe if the library lazily requires its sub-modules? However, I guess this should produce the same results when added to the spec_helper.rb of other large suites: ```ruby # Ractor.new { nil } # uncomment this to affect coverage results require 'coverage' Coverage.start # require library, set up rspec etc. RSpec.configuration.after(:suite) do # this number is greatly reduced and unstable when calling Ractor above p Coverage.result.values.sum { |arr| arr.sum(&:to_i) } end ``` I had this problem in [this library](https://github.com/jaynetics/character_set/). The problem affects simplecov users as well, as described [here](https://github.com/simplecov-ruby/simplecov/issues/1058). -- https://bugs.ruby-lang.org/