# Ruby 1.9.1 gem command - can't find user for 500

**URL:** <https://www.ruby-forum.com/t/ruby-1-9-1-gem-command-cant-find-user-for-500/179787>\
**Category:** Ruby\
**Created:** [December 3, 2009, 7:54pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-gem-command-cant-find-user-for-500/179787 "2009-12-03T19:54:10Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![stevedogers](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9dc877/32.png) [@stevedogers](https://www.ruby-forum.com/u/stevedogers)\
**Post date:** [December 3, 2009, 7:54pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-gem-command-cant-find-user-for-500/179787/1 "2009-12-03T19:54:10Z")

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Has anyone else encountered this error or can suggest a way to correct  
it?  
These errors occur when running the gem command under ruby 1.9.1.  
The same error occurs with a different user #(0) when run as root.  
Under 1.8.6 and 1.8.7, no error occurs.

## This is a fresh version of ruby built on a 64 bit machine OS: Linux - Fedora Core 11

bash-/ruby-1.9.1-p243$ ruby -v  
ruby 1.9.1p243 (2009-07-16 revision 24175) [i686-linux]  
bash-/ruby-1.9.1-p243$ gem install rake  
ERROR: While executing gem … (ArgumentError)  
can’t find user for 500  
bash-/ruby-1.9.1-p243$ gem list

\*\*\* LOCAL GEMS \*\*\*

## ERROR: While executing gem … (ArgumentError) can’t find user for 500

TIA for all replies,

– Steve D.

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**Author:** ![stevedogers](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9dc877/32.png) [@stevedogers](https://www.ruby-forum.com/u/stevedogers)\
**Post date:** [December 3, 2009, 8:24pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-gem-command-cant-find-user-for-500/179787/2 "2009-12-03T20:24:01Z")

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On Dec 3, 2009, at 10:51 , Steve D. wrote:

> bash-/ruby-1.9.1-p243$ gem install rake  
> ERROR: While executing gem … (ArgumentError)  
> can’t find user for 500  
> bash-/ruby-1.9.1-p243$ gem list
> 
> \*\*\* LOCAL GEMS \*\*\*
> 
> ERROR: While executing gem … (ArgumentError)  
> can’t find user for 500

no clue. run with --debug and/or --backtrace

that said… 1.9 ships with rake, so there is no reason to install it.

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<div class="post-metadata">

**Author:** ![stevedogers](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9dc877/32.png) [@stevedogers](https://www.ruby-forum.com/u/stevedogers)\
**Post date:** [December 3, 2009, 10:27pm UTC](https://www.ruby-forum.com/t/ruby-1-9-1-gem-command-cant-find-user-for-500/179787/3 "2009-12-03T22:27:31Z")

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On Fri, 4 Dec 2009 04:23:13 +0900  
Ryan D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> > * * *
> > 
> > can’t find user for 500
> 
> no clue. run with --debug and/or --backtrace
> 
> that said… 1.9 ships with rake, so there is no reason to install it.

Ryan,

OK. “gem install rake” was a bad choice, since it was included in 1.9.1.  
The same result happened with every other gem I attempted to install.  
The debug output indicated that there were library issues.

I reinstalled multiruby  
([http://blog.robseaman.com/2008/12/20/switching-between-ruby-1-8-1-9-with-multiruby](http://blog.robseaman.com/2008/12/20/switching-between-ruby-1-8-1-9-with-multiruby))  
and the problem seems to have gone away. I wish I had more time to  
explore the “can’t find user for xxx” message, but I believe it to be a  
side effect related to 32/64 bit library issues.

Now I just have to reinstall gems to all 3 ruby versions…

BTW, thanks for the laughs at the “Worst. Ideas. Ever.” presentation at  
RubyConf.