Error installing unicorn

Question

I am trying to run GitLab on my server. But the service won't start up. It puts out:

==> /var/log/gitlab/sidekiq/current /var/log/gitlab/unicorn/current <==
2016-01-26_16:35:06.79546 failed to start a new unicorn master
2016-01-26_16:35:06.80558 starting new unicorn master
2016-01-26_16:35:07.10485 Warning: the running version of Bundler is older than the version that created the lockfile. We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
2016-01-26_16:35:07.11661 bundler: command not found: unicorn
2016-01-26_16:35:07.12170 Install missing gem executables with `bundle install`

My System:

• Ubuntu 14.04

• Plesk 12.5

• Ruby 1.9.3

• Gem 1.8.23

• Bundler 1.11.2

I tried to run

gem install unicorn

But than I get the Error:

Building native extensions.  This could take a while...
ERROR:  Error installing unicorn:
    ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError)
    from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
    from extconf.rb:1:in `<main>'


Gem files will remain installed in /var/lib/gems/1.9.1/gems/kgio-2.10.0 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/kgio-2.10.0/ext/kgio/gem_make.out

I have no experience with ruby. So anyone has a suggestion what I'm doing wrong ?

Thanks in advance Dominic

Answer 1

Are you limited to Ruby 1.9.3? Currently the most stable version of Ruby is 2.3.0. Updating Ruby will probably fix this issue.

https://www.ruby-lang.org/en/downloads/

Alternatively, before updating Ruby, check out this thread. Here is a similar error someone had with Ruby 1.9.1. `require': no such file to load -- mkmf (LoadError)

It looks like people on that thread had success using build-essential:

sudo apt-get install build-essential