# How to determine which gems an app depends on?

**URL:** <https://www.ruby-forum.com/t/how-to-determine-which-gems-an-app-depends-on/124843>\
**Category:** Rails\
**Created:** [January 3, 2008, 12:56am UTC](https://www.ruby-forum.com/t/how-to-determine-which-gems-an-app-depends-on/124843 "2008-01-03T00:56:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![bbebop](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/cdc98d/32.png) [@bbebop](https://www.ruby-forum.com/u/bbebop)\
**Post date:** [January 3, 2008, 12:56am UTC](https://www.ruby-forum.com/t/how-to-determine-which-gems-an-app-depends-on/124843/1 "2008-01-03T00:56:12Z")

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I have an app for which script/server crashes on startup, probably  
because the platform doesn’t have one or more required gems  
installed. I’m wondering if there’s an easy way to determine which  
gems are required or missing. Thanks.

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<div class="post-metadata">

**Author:** ![bbebop](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/cdc98d/32.png) [@bbebop](https://www.ruby-forum.com/u/bbebop)\
**Post date:** [January 3, 2008, 4:33am UTC](https://www.ruby-forum.com/t/how-to-determine-which-gems-an-app-depends-on/124843/2 "2008-01-03T04:33:40Z")

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On 1/2/08, bbebop [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> I have an app for which script/server crashes on startup, probably  
> because the platform doesn’t have one or more required gems  
> installed. I’m wondering if there’s an easy way to determine which  
> gems are required or missing. Thanks.

You need to look for require statements that are failing. Start the  
server in development mode so you can get more explicit errors in the  
logs.

RAILS\_ENV=development script/server

tail -f log/development.log

–  
Greg D.  
[http://destiney.com/](http://destiney.com/)