Error with Performance/Sum inspecting code with a dynamic method name

[colinux]

Rubocop reports an error parsing this simplified code with cop Performance/Sum :

# frozen_string_literal: true

require "ostruct"

ary = [OpenStruct.new(crit1: 1, crit2: 5), OpenStruct.new(crit1: 2, crit2: 7)]

ary.define_singleton_method(:averagize) do |field|
  return unless any?

  local_sum = map(&field).sum # line reported
  (local_sum.to_f / size).round(1)
end

puts ary.averagize(:crit1)
puts ary.averagize(:crit2)

$ bundle exec rubocop -d tmp/debug-perf-sum.rb

For /Users/colin/code/hap: configuration from /Users/colin/code/hap/.rubocop.yml
configuration from /Users/colin/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/config/default.yml
configuration from /Users/colin/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/config/default.yml
Default configuration from /Users/colin/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/config/default.yml
configuration from /Users/colin/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rubocop-rails-2.9.1/config/default.yml
configuration from /Users/colin/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/rubocop-rails-2.9.1/config/default.yml
Inheriting configuration from /Users/colin/code/hap/.rubocop_todo.yml
Inspecting 1 file
Scanning /Users/colin/code/hap/tmp/debug-perf-sum.rb
An error occurred while Performance/Sum cop was inspecting /Users/colin/code/hap/tmp/debug-perf-sum.rb:10:14.
undefined method `source_range' for nil:NilClass

<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:231:in `method_call_with_args_range'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:147:in `autocorrect_sum_map'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:122:in `block (2 levels) in handle_sum_map_candidate'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/base.rb:339:in `correct'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/base.rb:126:in `add_offense'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:121:in `block in handle_sum_map_candidate'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:91:in `sum_map_candidate?'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:116:in `handle_sum_map_candidate'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-performance-1.9.2/lib/rubocop/cop/performance/sum.rb:86:in `on_send'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:136:in `public_send'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:136:in `block (2 levels) in trigger_restricted_cops'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:166:in `with_cop_error_handling'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:135:in `block in trigger_restricted_cops'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:134:in `each'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:134:in `trigger_restricted_cops'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:70:in `on_send'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:135:in `on_lvasgn'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:71:in `on_lvasgn'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `block in on_dstr'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `each'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `on_dstr'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:71:in `on_begin'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:158:in `on_block'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:71:in `on_block'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `block in on_dstr'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `each'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:137:in `on_dstr'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:71:in `on_begin'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-ast-1.4.0/lib/rubocop/ast/traversal.rb:20:in `walk'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/commissioner.rb:86:in `investigate'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/team.rb:157:in `investigate_partial'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cop/team.rb:83:in `investigate'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:315:in `inspect_file'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:259:in `block in do_inspection_loop'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:293:in `block in iterate_until_no_changes'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:286:in `loop'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:286:in `iterate_until_no_changes'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:255:in `do_inspection_loop'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:132:in `block in file_offenses'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:157:in `file_offense_cache'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:131:in `file_offenses'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:122:in `process_file'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:101:in `block in each_inspected_file'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:100:in `each'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:100:in `reduce'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:100:in `each_inspected_file'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:86:in `inspect_files'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/runner.rb:47:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/command/execute_runner.rb:26:in `block in execute_runner'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/command/execute_runner.rb:52:in `with_redirect'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/command/execute_runner.rb:25:in `execute_runner'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/command/execute_runner.rb:17:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/command.rb:11:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli/environment.rb:18:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli.rb:65:in `run_command'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli.rb:72:in `execute_runners'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/lib/rubocop/cli.rb:41:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/exe/rubocop:13:in `block in <top (required)>'
<rbenv>/lib/ruby/gems/2.6.0/gems/benchmark-0.1.1/lib/benchmark.rb:308:in `realtime'
<rbenv>/lib/ruby/gems/2.6.0/gems/rubocop-1.8.1/exe/rubocop:12:in `<top (required)>'
<rbenv>/bin/rubocop:23:in `load'
<rbenv>/bin/rubocop:23:in `<top (required)>'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `load'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:74:in `kernel_load'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli/exec.rb:28:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:463:in `exec'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:27:in `dispatch'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/cli.rb:18:in `start'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/exe/bundle:30:in `block in <top (required)>'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/bundler/friendly_errors.rb:124:in `with_friendly_errors'
<rbenv>/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/exe/bundle:22:in `<top (required)>'
./bin/bundle:3:in `load'
./bin/bundle:3:in `<main>'

---

$ bundle exec rubocop -V
1.8.1 (using Parser 3.0.0.0, rubocop-ast 1.4.0, running on ruby 2.6.6 x86_64-darwin19)
  - rubocop-performance 1.9.2
  - rubocop-rails 2.9.1