The best replacement for debug is trace.

The best alternatives to debug are rated as following:
★★★★★  trace
★★★★★  release
★★  release visual studio
★★  release dll
★★  info
★★  release build
★  release performance
★  info level
★  info log4j
★  release xcode
★  trace log4j
★  release c#
★  release c++
★  trace c
  verbose
  addin
  active debug
  release visual studio 2008
  release build net
  run
  release .net
  release net
  send error report
  release builds

Your alternative for debug is not listed? Suggest!
Speaking about debug, one probably shouldn't forget about gcc.

Other search terms related to debug and their ratings are:
★★★★★ gcc
★★★ g++
★ downloading iar
★ geany
toad
You have in mind a companion for debug and it is not yet here? Propose!



Google Trends

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debug
trace
release