[rb] Replace debug session with Bazel run_under flag

This helps to avoid conflicts with RubyMine built-in debugger.

Author: p0deje

.bazelrc

@@ -77,6 +77,7 @@ test:windows --test_env=PROGRAMFILES(X86)="C:\\Program Files (x86)"
 test --test_timeout=1800
 
 test:node_debug --test_output=streamed --test_strategy=exclusive --test_timeout=9999 --nocache_test_results
+test:ruby_debug --test_output=streamed --test_env=RUBY_DEBUG_FORK_MODE=parent --run_under="@bundle//:bin/rdbg --nonstop --open --command"
 
 # The RBE to use
 build:remote --bes_results_url=https://gypsum.cluster.engflow.com/invocation

README.md

@@ -274,7 +274,7 @@ echo 'RUBY_VERSION = "<X.Y.Z>"' > rb/ruby_version.bzl
 If you want to debug code in tests, you can do it via [`debug`](https://github.com/ruby/debug) gem:
 
 1. Add `binding.break` to the code where you want the debugger to start.
-2. Run `bazel test --test_output streamed <test>`. Streaming output is not required, but will clearly say when debugger starts.
+2. Run tests with  `ruby_debug` configuration: `bazel test --config ruby_debug <test>`.
 3. When debugger starts, run the following in a separate terminal to connect to debugger:
 
 ```sh

rb/spec/integration/selenium/webdriver/spec_helper.rb

@@ -17,14 +17,6 @@
 # specific language governing permissions and limitations
 # under the License.
 
-begin
-  require 'debug/session'
-  DEBUGGER__::CONFIG[:fork_mode] = :parent
-  DEBUGGER__.open(nonstop: true)
-rescue LoadError
-  # not supported on JRuby and TruffleRuby
-end
-
 require 'rubygems'
 require 'time'
 require 'rspec'