Unable to resolve Ruby error (missing psych)

Question

Whenever I run something with Ruby on my server, I get the following error:

/usr/local/rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/yaml.rb:56:in `

        

Answer 1

Make sure your Redhat machine has a valid subscription:

# subscription-manager list 

+-------------------------------------------+
    Installed Product Status
+-------------------------------------------+
Product Name:   Red Hat Enterprise Linux Server
Product ID:     69
Version:        7.1
Arch:           x86_64
Status:         Subscribed
Status Details: 
Starts:         06/13/2014
Ends:           06/12/2015

Status must say "Subscribed". If not, then suffer through getting a login and maybe purchasing a subscription at https://access.redhat.com/management/consumers.

When that's done, run

# subscription-manager repos --enable rhel-7-server-optional-rpms

then libyaml-devel will install OK.