From: "Peña, Botp" <botp@...>
Date: 2007-05-31T10:38:26+09:00
Subject: `concat': can't modify frozen string in benchmark.rb

Hi All,

C:\family\ruby>cat test.rb
def f(command_here)
   `#{command_here}`
end
a  =  {  "Local copy"=>"copy test.txt test.txt2"  }
require 'benchmark'
Benchmark.bmbm do |x|
   a.each do |k,v|
      x.report(k) { f v }
   end
end

C:\family\ruby>ruby test.rb
c:/ruby/lib/ruby/1.8/benchmark.rb:334:in `concat': can't modify frozen string (T
ypeError)
        from c:/ruby/lib/ruby/1.8/benchmark.rb:334:in `report'
        from test.rb:12
        from test.rb:11:in `each'
        from test.rb:11
        from c:/ruby/lib/ruby/1.8/benchmark.rb:250:in `bmbm'
        from test.rb:10
C:\family\ruby>

if i comment out line 334 in benchmark.rb like so,

     #label.concat ' '

It works.
It also works for the ff cases
   x.report(k) { f v }
   x.report() { f v }
   x.report("") { f v }
   x.report("test") { f v }

What is the relevance of line 334 in benchmark.rb?
If the line is important, how can I fix my program so I can pass a var in x.report?

thank you and kind regards -botp