# \[ANN\] ruby backtracer (quality screen output) updated

**URL:** <https://www.ruby-forum.com/t/ann-ruby-backtracer-quality-screen-output-updated/166960>\
**Category:** Ruby\
**Created:** [May 1, 2009, 1:42pm UTC](https://www.ruby-forum.com/t/ann-ruby-backtracer-quality-screen-output-updated/166960 "2009-05-01T13:42:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![rogerdpack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/45deac/32.png) [@rogerdpack](https://www.ruby-forum.com/u/rogerdpack)\
**Post date:** [May 1, 2009, 1:42pm UTC](https://www.ruby-forum.com/t/ann-ruby-backtracer-quality-screen-output-updated/166960/1 "2009-05-01T13:42:27Z")

</div>

Pleased to announce a new version of ruby\_backtracer.

Here’s the readme.

ruby\_backtracer: a library to output higher quality backtraces if an  
unhandled exception is raised

ex:  
running given script examples/crash.rb used to output:  
examples\>ruby crash.rb  
crash.rb:2:in `go2': unhandled exception from crash.rb:6:in `go’  
from crash.rb:9

now outputs:  
examples\>ruby -r…/backtrace\_with\_code\_and\_locals crash.rb

unhandled exception: crash.rb:2: raise  
locals: {“a”=\>“3”, “b”=\>55}  
from:  
crash.rb:1 go2(a=\>3, b=\>55)  
locals: {“a”=\>“3”, “b”=\>55}  
crash.rb:5 go(a=\>3)  
locals: {“a”=\>“3”}

Now wasn’t that prettier?

There are several other tracing options provided, if you don’t want as  
much output, or want more speed. Specify which by script name.

ex: backtrace\_nothing\_swallowed.rb outputs the same as the default  
exception output, except it doesn’t have the  
…skip 24 lines…  
line in the middle (also no speed slowdown, and no local variables  
displayed).

Try them out by running test\_all.rb in the examples folder, or eyeball  
the example output files in examples/example\_output\*

[http://github.com/rogerdpack/ruby\_backtracer/tree/master](http://github.com/rogerdpack/ruby_backtracer/tree/master)

Note: some options depends on ruby-debug [MRI] gem, some don’t.

To install clone from github, above, then -rscriptname.

related projects: unroller,  
[eigenclass.org](http://eigenclass.org/hiki/method+arguments+via+introspection),  
liveconsole, ruby-debug

Thanks!  
-=r