# Segv when Fiber#pass twice

**URL:** <https://www.ruby-forum.com/t/segv-when-fiber-pass-twice/105715>\
**Category:** Development\
**Created:** [June 1, 2007, 5:51pm UTC](https://www.ruby-forum.com/t/segv-when-fiber-pass-twice/105715 "2007-06-01T17:51:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sheepman](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepman](https://www.ruby-forum.com/u/sheepman)\
**Post date:** [June 1, 2007, 5:51pm UTC](https://www.ruby-forum.com/t/segv-when-fiber-pass-twice/105715/1 "2007-06-01T17:51:33Z")

</div>

e$B$3$s$P$s$O!"e(Bsheepman e$B$G$9!#e(B

trunk e$B$G!"=\*N;$7$?e(B Fiber e$B$Ke(B pass e$B$r8F$V$He(B segv  
e$B$7$^$9!#e(B

$ cat f.rb  
fbr = Fiber.new do  
end  
fbr.pass  
fbr.pass

## $ ruby-1.9 -v f.rb ruby 1.9.0 (2007-06-01 patchlevel 0) [i686-linux] : – stack frame ------------ 0000 (0x8171eb0): 00000000 \<- lfp \<- dfp – control frame ---------- c:0001 p:---- s:0001 b:-001 l:000000 d:000000 ------

## – backtrace of native function call (Use addr2line) – 0x80c1a9c 0x80d506d 0x80c63c7 0x805953c 0x8059554 0x805958f 0x8056dd4 0x400dcc1f 0x8056d19

[BUG] rb\_fiber\_start: unreachable  
ruby 1.9.0 (2007-06-01) [i686-linux]

zsh: abort ruby-1.9 -v f.rb

---

<div class="post-metadata">

**Author:** ![sheepman](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d07c76/32.png) [@sheepman](https://www.ruby-forum.com/u/sheepman)\
**Post date:** [June 4, 2007, 3:52am UTC](https://www.ruby-forum.com/t/segv-when-fiber-pass-twice/105715/2 "2007-06-04T03:52:25Z")

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e$B!!$5$5$@$G$9!#e(B

sheepman e$B$5$s$O=q$-$^$7$?e(B:

> trunk e$B$G!"=\*N;$7$?e(B Fiber e$B$Ke(B pass e$B$r8F$V$He(B segv e$B$7$^$9!#e(B

e$B!!e(BFiberError e$B$rJV$9$h$&$K$7$^$7$?!#e(B

e$B!!$J$\*!"e(B#pass e$B$Oe(B #yield  
e$B$KJQ99$7$^$7$?!#$3$l$O!"e(BProc#yield e$B?7e(B  
e$B@\_$r\<u$1$F$NJQ99$G$9!#e(B

e$B!!e(BFiber.new{|x| p x}.yield(:ok) #=\> :ok

e$B!!e(BProc e$B$K$7$F$b0UL#$,DL$k$H$3$m$H$+!#e(B