# How to add dependency for existing gems

**URL:** <https://discuss.elastic.co/t/how-to-add-dependency-for-existing-gems/48343>\
**Category:** Logstash\
**Created:** [April 25, 2016, 5:22pm UTC](https://discuss.elastic.co/t/how-to-add-dependency-for-existing-gems/48343 "2016-04-25T17:22:43Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![BINLEI\_XUE](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/binlei_xue/32/2205_2.png) [@BINLEI\_XUE](https://discuss.elastic.co/u/BINLEI_XUE)\
**Post date:** [April 25, 2016, 5:22pm UTC](https://discuss.elastic.co/t/how-to-add-dependency-for-existing-gems/48343/1 "2016-04-25T17:22:43Z")

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Hi All,

I am new to jruby

I want to add gssapi support for logstash-output-elasticsearch

so I modify some code on elasticsearch-transport gem

```auto
export GEM_HOME=$LOGSTASH_HOME/vendor/bundle/jruby/1.9
export GEM_PATH=""

```

`vendor/jruby/bin/jruby vendor/jruby/bin/gem install gssapi`

after I start the logstash instance, I got `no such file to load -- gssapi` error

Since I already install gssapi, why I get such error? How can I solve this error?

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<div class="post-metadata">

**Author:** ![BINLEI\_XUE](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/binlei_xue/32/2205_2.png) [@BINLEI\_XUE](https://discuss.elastic.co/u/BINLEI_XUE)\
**Post date:** [April 26, 2016, 12:13pm UTC](https://discuss.elastic.co/t/how-to-add-dependency-for-existing-gems/48343/2 "2016-04-26T12:13:34Z")

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one solution, after install new gem, add the gem in the logstash gem file, run logstash once to update the lock file

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 5:00am UTC](https://discuss.elastic.co/t/how-to-add-dependency-for-existing-gems/48343/3 "2017-07-06T05:00:31Z")

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