An error occurred while installing nokogiri

Summary:
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During bundle install nokogiri shows some errors. we need to install associated packages for nokogiri gem

Step 1:
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Install associated packages

$ sudo apt-get install libxslt-dev libxml2-dev

Step 2:
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Now start the bundle install

Gem install pg error

Summary:
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Install pg without any installation errors

Step 1:
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Before install 'pg' Gem we need to install the following dependency package

$ sudo apt-get     install libpq-dev

Step 2:
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Install 'pg' gem

$ gem install pg

Install gem without ri-documentaions

Summary:
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During Gem installation skip the ri and Rdoc installation process; Create a .gemrc file from home directory and paste the following code and save.

Step 1:
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Open terminal create .gemrc

$ touch .gemrc

Step 2:
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Add the following line in that file , then save and close the file. Start install gem without any RDocs

gem: --no-ri --no-rdoc