ruby1.9.1-dev

[BadWizard]

I am new to Docker and wanted to follow your demonstration. I get this error:

E: Package 'ruby1.9.1-dev' has no installation candidate
/bin/sh: 1: gem: not found
The command '/bin/sh -c apt-get install ruby1.9.1 ruby1.9.1-dev ; gem install asciidoctor pygments.rb ;' returned a non-zero code: 127

when I run the Docker file. Any suggestion how to fix this? Thanks

[shwethabetageri]

sudo apt-get install ruby1.9.1-devReading package lists... Done
Building dependency tree
Reading state information... Done
Package ruby1.9.1-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'ruby1.9.1-dev' has no installation candidate

Can you please help me to solve this issue