improved support for assertions and logging in C/C++

 GNU Nana is a library that provides improved support for assertion checking,
 logging, and performance measurement in C/C++, when compared with the
 standard assert.h mechanism. Avoid maintaining a source version without
 assertions and logging for production use or using non-standard macros.
 .
  - Space/time efficient assertion checking.
  - Space/time efficient program logging to file, console, process,
    or circular buffer in memory.
  - Selectively enable and disable assertion checking and logging both at
    compile and run time. Configure action following assertion failure.
  - Logging via inline C code (as in <assert.h>) or by extraction of
    commands for gdb which results in no performance cost unless
    running in the debugger.
  - Statement and function-level source tracing under GDB.
  - Code-to-HTML converter giving only details of your interface and
    pre/postconditions (similar to Eiffel short form).
  - Official GNU package.