Rakefile in ruby_parser-3.0.0.a3 vs Rakefile in ruby_parser-3.0.0.a4

@@ -137,11 +137,11 @@
   puts
   sh "diff -du racc19.txt yacc19.txt | wc -l"
 end
 
 task :debug => :isolate do
-  ENV["V"] ||= "18"
+  ENV["V"] ||= "19"
   Rake.application[:parser].invoke # this way we can have DEBUG set
 
   $: << "lib"
   require 'ruby_parser'
 
@@ -167,8 +167,17 @@
     ss = parser.lexer.src
     src = ss.string
     lines = src[0..ss.pos].split(/\n/)
     abort "on #{file}:#{lines.size}"
   end
+end
+
+task :extract => :isolate do
+  ENV["V"] ||= "19"
+  Rake.application[:parser].invoke # this way we can have DEBUG set
+
+  file = ENV["F"] || ENV["FILE"]
+
+  ruby "-Ilib", "bin/ruby_parse_extract_error", file
 end
 
 # vim: syntax=Ruby