# \[Bug:trunk\] backtrace of SystemStackError disappeared

**URL:** <https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890>\
**Category:** Development\
**Created:** [March 28, 2010, 5:01pm UTC](https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890 "2010-03-28T17:01:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [March 28, 2010, 5:01pm UTC](https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890/1 "2010-03-28T17:01:34Z")

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e$B1sF#$G$9!#e(B

e$B$J$\<$+e(B SystemStackError  
e$B$N;~$N%P%C%/%H%l!\<%9$,=P$J$/$J$C$F$$$k$h$&$G$9!#e(B

$ ./ruby -ve ‘def foo; bar; end; def bar; foo; end; def baz; foo; end;  
baz’  
ruby 1.9.2dev (2010-03-26 trunk 27063) [i686-linux]  
-e:1: stack level too deep (SystemStackError)

$ ruby-1.9.1-p378 -ve ‘def foo; bar; end; def bar; foo; end; def baz;  
foo; end; baz’  
ruby 1.9.1p378 (2010-01-10 revision 26273) [i686-linux]  
-e:1:in `foo': stack level too deep (SystemStackError) from -e:1:in`bar’  
from -e:1:in `foo' from -e:1:in`bar’  
from -e:1:in `foo' from -e:1:in`bar’  
from -e:1:in `foo' from -e:1:in`bar’  
from -e:1:in `foo' ... 8720 levels... from -e:1:in`bar’  
from -e:1:in `foo' from -e:1:in`baz’  
from -e:1:in `’

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [March 28, 2010, 5:43pm UTC](https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890/2 "2010-03-28T17:43:42Z")

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e$B1sF#$G$9!#e(B

2010e$BG/e(B3e$B7ne(B29e$BF|e(B0:00 Yusuke ENDOH [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> e$B$J$\<$+e(B SystemStackError e$B$N;~$N%P%C%/%H%l!\<%9$,=P$J$/$J$C$F$$$k$h$&$G$9!#e(B

git bisect e$B@h@8$K$h$k$He(B r25680 e$B$,860x$N$h$&$G$9!#e(B

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [April 20, 2010, 4:56pm UTC](https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890/3 "2010-04-20T16:56:38Z")

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e$B%A%1%C%He(B #3033 e$B$,99?7$5$l$^$7$?!#e(B (by Yusuke E.)

e$B%9%F!\<%?%9e(B Opene$B$+$ie(BRejectede$B$KJQ99e(B  
Target version 1.9.2e$B$K%;%C%He(B  
ruby -v -e$B$K%;%C%He(B

e$B1sF#$G$9!#e(B

r25680  
e$B$N%3%_%C%H$r$A$c$s$H$_$k$H!“$^$D$b$H$5$s$,0U?^E\*$KJQ99$7$?$h$&e(B  
e$B$J$N$G!”%P%0$G$O$J$$$h$&$G$9!#e(Brejected e$B$H$7$^$9!#e(B

# e$B!Ve(Bmatz

e$B$r@bF@$9$kJ}K!!W$N!V\>JN,$N0U?^$rB:=E$7$F$$$k!W$,\>C$($A$c$C$?e(B

# [http://www.a-k-r.org/pub/howto-persuade-matz-rubykaigi2008.pdf](http://www.a-k-r.org/pub/howto-persuade-matz-rubykaigi2008.pdf)

## – Yusuke E. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

[http://redmine.ruby-lang.org/issues/show/3033](http://redmine.ruby-lang.org/issues/show/3033)

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<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [April 29, 2010, 9:48am UTC](https://www.ruby-forum.com/t/bug-trunk-backtrace-of-systemstackerror-disappeared/185890/4 "2010-04-29T09:48:16Z")

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e$B%A%1%C%He(B #3033 e$B$,99?7$5$l$^$7$?!#e(B (by Evgeniy D.)

I think that returning String instead of an Array as Exception#backtrace  
here [ruby/eval.c at trunk · shyouhei/ruby · GitHub](http://github.com/shyouhei/ruby/blob/trunk/eval.c#L382)  
is breaking other code expectation about backtrace being enumerable.

The real life example is RSpec:

/usr/local/rvm/gems/ruby-1.9.2-head/gems/rspec-core-2.0.0.beta.7/lib/rspec/core/formatters/base\_formatter.rb:127:in  
`read_failed_line': undefined method `detect’ for  
“faster\_open\_struct.rb:0”:String (NoMethodError)

## (link to the code [rspec-core/lib/rspec/core/formatters/base\_formatter.rb at master · rspec/rspec-core · GitHub](http://github.com/rspec/rspec-core/blob/master/lib/rspec/core/formatters/base_formatter.rb#L125) )

[http://redmine.ruby-lang.org/issues/show/3033](http://redmine.ruby-lang.org/issues/show/3033)