Greetings, I’m installing a fresh version of OpenProject, and I’m following this tutorial: https://www.openproject.org/projects/openproject/wiki/Installation_OpenProject_3_0

I’m using: Linux debian 3.2.0-4-686-pae #1 SMP Debian 3.2.54-2 i686 GNU/Linux

Until step 3.2, everything works great, but when I tried to install gems, I’m getting an error with JSON 1.8.1, this is my Gemfile.plugins file:

gem "openproject-plugins", git: "https://github.com/opf/openproject-plugins.git", :branch => "stable"
gem "openproject-help_link", :git => "https://github.com/finnlabs/openproject-help_link.git", :branch => "stable"
gem "openproject-backlogs", :git => "https://github.com/finnlabs/openproject-backlogs.git", :branch => "stable"
gem 'openproject-costs', :git => 'https://github.com/finnlabs/openproject-costs.git', :branch => "stable"
gem 'openproject-global_roles', :git => 'https://github.com/finnlabs/openproject-global_roles.git', :branch => "stable"
gem 'openproject-meeting', :git => 'https://github.com/finnlabs/openproject-meeting.git', :branch => "stable"
gem 'openproject-my_project_page', :git => 'https://github.com/finnlabs/openproject-my_project_page.git', :branch => "stable"
gem 'openproject-pdf_export', :git => 'https://github.com/finnlabs/openproject-pdf_export.git', :branch => "stable"
gem 'openproject-documents', :git => 'https://github.com/opf/openproject-documents.git', :branch => "stable"
gem 'openproject-translations', :git => 'https://github.com/opf/openproject-translations.git', :branch => "stable"

when I try t install gems with:

bundle install --without mysql mysql2 sqlite development test rmagick

.

This is the output:

Updating https://github.com/opf/openproject-plugins.git
Updating https://github.com/finnlabs/openproject-help_link.git
Updating https://github.com/finnlabs/openproject-backlogs.git
Updating https://github.com/finnlabs/openproject-costs.git
Updating https://github.com/finnlabs/openproject-global_roles.git
Updating https://github.com/finnlabs/openproject-meeting.git
Updating https://github.com/finnlabs/openproject-my_project_page.git
Updating https://github.com/finnlabs/openproject-pdf_export.git
Updating https://github.com/opf/openproject-documents.git
Updating https://github.com/opf/openproject-translations.git
Fetching gem metadata from https://rubygems.org/........
Fetching additional metadata from https://rubygems.org/..
Resolving dependencies.....
Using rake 10.1.0
Using Ascii85 1.0.2
Using i18n 0.6.8
Using multi_json 1.9.2
Using activesupport 3.2.18
Using builder 3.0.4
Using activemodel 3.2.18
Using erubis 2.7.0
Using journey 1.0.4
Using rack 1.4.5
Using rack-cache 1.2
Using rack-test 0.6.2
Using hike 1.2.3
Using tilt 1.4.1
Using sprockets 2.2.2.backport2
Using actionpack 3.2.18
Using mime-types 1.25.1
Using polyglot 0.3.3
Using treetop 1.4.15
Using mail 2.5.4
Using actionmailer 3.2.18
Using arel 3.0.3
Using tzinfo 0.3.38
Using activerecord 3.2.18
Using activeresource 3.2.18
Using acts_as_list 0.2.0
Using acts_as_silent_list 1.2.0
Using afm 0.2.0
Using awesome_nested_set 2.1.6
Using bundler 1.6.2
Using climate_control 0.0.3
Using cocaine 0.5.4
Using coderay 1.0.9
Using coffee-script-source 1.6.2
Using execjs 1.4.0
Using coffee-script 2.2.0
Using rack-ssl 1.3.3

Gem::Installer::ExtensionBuildError: 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 /tmp/bundler20140514-9570-1n4foxb/json-1.8.1/gems/json-1.8.1 for inspection.
Results logged to /tmp/bundler20140514-9570-1n4foxb/json-1.8.1/gems/json-1.8.1/ext/json/ext/generator/gem_make.out
An error occurred while installing json (1.8.1), and Bundler cannot continue.
Make sure that `gem install json -v '1.8.1'` succeeds before bundling.

And if I’m trying to install Json with

gem install json -v '1.8.1'

I’m getting:

Fetching: json-1.8.1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed json-1.8.1
Parsing documentation for json-1.8.1
unable to convert "\xC0" from ASCII-8BIT to UTF-8 for lib/json/ext/generator.so, skipping
unable to convert "\x90" from ASCII-8BIT to UTF-8 for lib/json/ext/parser.so, skipping
Installing ri documentation for json-1.8.1
1 gem installed

But when I tried to install the gems against, I’m getting the same error =S.

Gem::Installer::ExtensionBuildError: 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 /tmp/bundler20140514-9570-1n4foxb/json-1.8.1/gems/json-1.8.1 for inspection.
Results logged to /tmp/bundler20140514-9570-1n4foxb/json-1.8.1/gems/json-1.8.1/ext/json/ext/generator/gem_make.out
An error occurred while installing json (1.8.1), and Bundler cannot continue.
Make sure that `gem install json -v '1.8.1'` succeeds before bundling.

After that, I try to install OpenProject without any plugins, I’m getting the same error =S.

The version of ruby:

ruby -v
ruby 2.0.0p457 (2014-03-03) [i386-linux-gnu]