Yesterday I've encountered a sudden bug: my four years old script rafused to work. After a slight rewrite I got some kind of descriptive symptom in the syslog:
Fatal: Bad file descriptor
/usr/local/lib/ruby/gems/1.8/gems/deprecated-2.0.1/lib/deprecated.rb:199:in `write'
/usr/local/lib/ruby/gems/1.8/gems/deprecated-2.0.1/lib/deprecated.rb:199
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
/usr/local/lib/ruby/site_ruby/1.8/dbi.rb:48
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `require' /usr/work/flow-tools/flow-pg_import:13