Backtrace

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Comment: Try to get better backtraces
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A backtrace shows a listing of which program functions are still active. Since functions are nested when they are called, the program must record where it left one function, to jump into an inner one. It does this on the stack, which we dump for the backtrace,

By getting a backtrace at the point of a bug, a developer may be able to isolate where that bug is, because it will narrow down to the function, or even the line, that caused the erroneous behaviour.

= Generation =
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 1. Make sure the GNU Debugger is installed. {{{
apt-get install gdb
}}}
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gdb <program> gdb <program> 2>&1 | tee gdb.txt
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(gdb) thread apply all bt }}}

 1. If the output gets very long, you might want to use: {{{
(gdb) set logging file backtrace.txt
(gdb) set logging on
}}} beforehand.

 1. Include the complete output from GDB in your bug report.		 (gdb) backtrace
(gdb) thread apply all backtrace
}}}
 1. Attach the complete output from GDB, contained in gdb.txt, in your bug report.

A backtrace shows a listing of which program functions are still active. Since functions are nested when they are called, the program must record where it left one function, to jump into an inner one. It does this on the stack, which we dump for the backtrace,

By getting a backtrace at the point of a bug, a developer may be able to isolate where that bug is, because it will narrow down to the function, or even the line, that caused the erroneous behaviour.

Generation

Please ensure you have packages with debug symbols installed. You can do this by following the instructions at DebuggingProgramCrash.

  1. Make sure the GNU Debugger is installed. 

    apt-get install gdb

  2. Start the program under control of gdb: 

    gdb <program> 2>&1 | tee gdb.txt
(gdb) handle SIG33 pass nostop noprint
(gdb) run <arguments, if any>
  3. The program will start. Perform any actions necessary to reproduce the crash

  4. Retrieve a backtrace of the crash: 

    (gdb) backtrace
(gdb) thread apply all backtrace
  5. Attach the complete output from GDB, contained in gdb.txt, in your bug report.

Backtrace (last edited 2022-12-20 22:15:16 by sergiodj)