I tried this command in my PHP workspace as shown on the c9 homepage:
$ sudo apt-get install imagemagick
But the module did not install. I got this response:
Reading package lists... Done Building dependency tree Reading state information... Done Package imagemagick 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 'imagemagick' has no installation candidate
What can I do to install this module successfully?