installing rails with gem , error loading command

问题:

I'm try to install rails on Debian. when run this command

gem install rails

I gave this error:

ERROR:  Loading command: install (LoadError)
    cannot load such file -- zlib
ERROR:  While executing gem ... (NoMethodError)
    undefined method ``invoke_with_build_args' for nil:NilClass

even when I try this command: gem install I gave this error:

ERROR:  Loading command: install (LoadError)
    cannot load such file -- zlib
ERROR:  While executing gem ... (NoMethodError)
    undefined method ``invoke_with_build_args' for nil:NilClass

I used this link to build ruby from sources ruby 2.1.2 build instruction

what can I do to overcome this error?

回答1:

For who compile from source, they must checked dependencies. I think you need to install this library :

sudo apt-get install libssl-dev

Then you must recompiled ruby and everything worked.

回答2:

You need to install the zlib development headers.

Refer to your OS's package manager instructions on how to do this.

On a RedHat derivative it would look something like this:

sudo yum install zlib-devel

For ubuntu:

sudo apt-get install zlib1g-dev

Hope this helps