Howto: Install RMagick on Windows 64 bits

I ran into a lot of problems trying to install RMagick on my 64bits Windows, but finally succeeded.

Here is how:

1. Install ImageMagick: version 6.6.9-5 32 bits. The version is important: I tried with 64bits versions, and also with 6.6.9-9 and 6.7.* versions and it failed miserably. You can find it here. Don’t forget to include development headers for C and C++ and also modify the PATH environment variable during the installation process.
2. Install the Ruby Development Kit. You can find it here.
3. Modify a little header in the DevKit. Search for the file /mingw/include/sys/types.h, and replace int with long at line 115:

   #ifndef _SIGSET_T_
   #define	_SIGSET_T_
   typedef int	_sigset_t;
   
   #ifndef	_NO_OLDNAMES
   typedef _sigset_t	sigset_t;
   #endif
   #endif	/* Not _SIGSET_T_ */
   
   #ifndef _SSIZE_T_
   #define _SSIZE_T_
   typedef long _ssize_t;
   
   #ifndef	_NO_OLDNAMES
   typedef _ssize_t ssize_t;
   #endif
   #endif /* Not _SSIZE_T_ */ 
   

4. In a terminal, modify your environment this way:

   set DFImageMagick=<ImageMagickInstallationPath>
   set CPATH=%DFImageMagick%\include;%CPATH%
   set LIBRARY_PATH=%DFImageMagick%\lib;%LIBRARY_PATH%
   

5. Install RMagick gem:

   gem install rmagick
   

This worked for me, I hope it will help others.