Ruby on rails.. rails server command, strange output? [duplicate] - ruby-on-rails

Question

I'm running a clean install of Ruby 2.2.1 on Windows 8.1 with DevKit. After the installation I run:
gem install rails
rails new testapp
cd testapp
rails server
leaving everything else at default.
The process fails at the last line when, instead of running the server, I get the error message
in 'require': cannot load such file -- 'nokogiri\nokogiri' (LoadError)
It happens every time and I've looked around and tried everything I found to fix it, but nothing so far has worked.
What is the problem here and how do I get a simple test Rails app to work?

Answer 1

Nokogiri doesn't support Ruby 2.2 on Windows yet. The next release will. See https://github.com/sparklemotion/nokogiri/issues/1256
Nokogiri doesn't support native builds (e.g. with devkit) on Windows. Instead it provides gems containing prebuilt DLLs.
There's a discussion which you may want to join or watch on the topic of devkit build support here: https://github.com/sparklemotion/nokogiri/issues/1190

Answer 2

First, uninstall the version of Nokogiri you currently have with:
gem uninstall nokogiri
Download Nokogiri 1.6.6.2 (x64) or Nokogiri 1.6.6.2 (x86)
Install this version locally using:
gem install --local C:\Users\$user$\Downloads\nokogiri-1.6.6.2-x64-mingw32.gem
or if you're running 32bit Ruby:
gem install --local C:\Users\$user$\Downloads\nokogiri-1.6.6.2-x86-mingw32.gem
The path may differ depending on where you downloaded the file to.
Try to start the server again using ruby bin\rails server, and it should work.

Answer 3

I got Nokogiri running with Ruby 2.2 on Windows 10 with a mix of Mike Dalessios and Julios answer:
Look for the latest version of Nokogiri in Nokogiri's github repo.
Run gem uninstall nokogiri.
Add gem "nokogiri", ">= 1.6.7.rc" to your Gemfile.
Run bundle install.
Run bundle update nokogiri if bundle has locked Nokogiri at some version.

Answer 4

Fix
Bundle install (gets Nokogiri files)
Browse to ruby_dir\lib\ruby\gems\2.2.0\gems\nokogiri-1.6.6.2\ext\nokogiri
Open extconf.rb
Add dir_config('iconv').any? or pkg_config('libiconv') to #376
Download MinGW64 & MSYS folders from Mega
Add them to PATH in Windows (remove Devkit path refs - it doesn't work)
Download libxml2,libxslt, iconv libraries (or here)
Run ruby extconf.rb --platform=ruby --n --use-system-libraries referencing downloaded libraries
Run make
Run make install
Steps
Bundle Install
First step is to bundle.
This will put the nokogiri gem on your machine without running the pre-packaged compiler (which mostly doesn't work in Windows).
This will show Nokogiri as installed:
Browse
Browse to the nokogiri folder, to find ext/nokogiri/extconf.rb:
Open extconf.rb
... and add dir_config('iconv').any? or pkg_config('libiconv') to #376
Standard Nokogiri installs "rely" on the libxml2 inclusion of iconv - we need to explicitly define it, otherwise iconv.h is missing errors will occur.
Add Toolchain
Don't use devkit for this - it doesn't work.
You need MinGW:
I have zipped my exact MinGW64 and MSYS64 folders on Mega (key: !FJtcq25l-QMsNltCxllMhc1IGqORvap8xv8gWxSUbDA):
Add to PATH
This gives access to gcc & make (both required):
Remove the devkit ref from your path, and add the following:
MINGW64_PATH/bin
MSYS64_PATH/bin
Download Libs
I have added the libs to Mega:
You will unzip them here:
All the libs are from this source.
Run extconf.rb
Once libs are on your system, you can run ruby extconf.rb to configure the build:
32bit
ruby extconf.rb --platform=ruby -N -- --use-system-libraries --with-xml2-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/32bit/libxml2-2.9.2-win32-x86 --with-xml2-include=C:/Dev/Dependencies/Ruby/lib/nokogiri/32bit/libxml2-2.9.2-win32-x86/include/libxml2 --with-iconv-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/32bit/iconv-1.14-win32-x86 --with-xslt-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/32bit/libxslt-1.1.28-win32-x86
64bit
#64
ruby extconf.rb --platform=ruby -N -- --use-system-libraries --with-xml2-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/64bit/libxml2-2.9.2-win32-x86_64 --with-xml2-include=C:/Dev/Dependencies/Ruby/lib/nokogiri/64bit/libxml2-2.9.2-win32-x86_64/include/libxml2 --with-iconv-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/64bit/iconv-1.14-win32-x86_64 --with-xslt-dir=C:/Dev/Dependencies/Ruby/lib/nokogiri/64bit/libxslt-1.1.28-win32-x86_64
make
This may create errors / warnings, as long as it says "Error 1 (ignored)", it should be okay.
Following that, use make install:
Then browse to your Rails installation and run rails s:
Explanation
To give context:
Ruby 2.2+ on Windows doesn't compile the extensions Nokogiri requires.
The extensions of a gem are the extra dependencies (libraries) it uses.
They are built when you install the gem:
Extensions
Lack of extensions is preventing Nokogiri from running.
Extensions exist in the ext folder of a gem (you can read about them here):
Mysql2,RMagick,PGSQL, Nokogiri etc all use extensions/libraries.
This is why - on Windows - you have to use custom switches (--with-opt-dir) when installing the gem. This gives Ruby / the shell / (cmd) the required lib / include directories required to build the gem's files (it's the equivalent of how PATH works).
On Linux/Mac, these directories are managed with the respective package managers (brew/apt-get). Windows does not have this, so you have to install the extensions manually.
Because Windows does not have a standard set of libraries, you have to download them yourself. You also have to build them yourself (which is tricky).
The fix for Nokogiri install is to use the right libraries and build tools to get the gem installed.
Build
The difference with Ruby 2.2+ is the gem will "install" without showing any exceptions. You think it has installed, only to find Rails does not load (hence the nokogiri/nokogiri.so error).
This means you have to make sure you have the files on your system, and run the compiler to install them.
The above documentation should show you how to do that.