trace_1.rb

line_tracer = TracePoint.new(:line) do |tp|
  p [tp.path, tp.lineno]
end

RSpec.configure do |config|
  # enable for each test case
  config.around do |example|
    line_tracer.enable do 
      example.run
    end
  end
end

trace_2.rb

current_id = nil
data = Hash.new { |h, example_id| h[example_id] = [] }

line_tracer = TracePoint.new(:line) do |tp|
  if record?(tp.path) # tell if we should record this event or not
    data[example_id] << [tp.path, tp.lineno]
  end
end
  
RSpec.configure do |config|
  config.around do |example|
    current_id = example.id
    line_tracer.enable do 
      example.run
    end
    flush(data) # write and clear huge data on each test case
  end
end