Ruby eventmachine install

System Environment: Windows 7 SP1

Ruby version: 1.9.2-P0

Devkit version: 4.5?

 

When you install eventmachine in this environment, errors are always reported.

 

Building native extensions. This cocould take a while...
Error: Error installing eventmachine:
Error: failed to build gem native extension.

 

This prompt keeps going, and there is still one more difficult error, which is the c compilation error. Later, I found two methods on the Internet.

1: gemInstall Eventmachine-win32, which seems to be installed in a lower version

2: gemInstall Eventmachine -- pre, which seems to be installed in Beta 1.0.0 .. I don't know where this version comes from .. -- Pre doesn't know what it is...