GDL - GNU Data Language

Hi I have been trying to install gdl on a linux mint machine, and it appears to have been successful. But, when I try to run it by typing 'gdl' I get the following error: gdl: symbol lookup error: /usr/local/lib/libreadline.so.6: undefined symbol: UP As far as I can tell I have the most recent versions of gdl and readline and have tried searching online for information but have found nothing particularly helpful. I'm also not very familiar with linux only having used it at university where everything was nicely set up for me so I apologise if this post is not relevant. Thanks for any help you can give me. :)