Simple Captcha setup problem

Zhenning Guan wrote:

$ rake simple_captcha:setup rake aborted! libMagickCore.so.1: cannot open shared object file: No such file or directory - /usr/lib/ruby/site_ruby/1.8/x86_64-linux/RMagick.so

(See full trace by running task with --trace)

how can I fix it?

This is because it is unable to find the library files. The best thing to do would be to login as root and issue

ldconfig /usr/lib

alternatively, try exporting the path of libs to current path