Dear admins,
Please restore the original post.
The proposed “official” way to use amdgpu-pro-install work only after a successful installation of the whole package from AMD. The caveat is the installation can be compleated ONLY on Ubuntu 18.04.
In a couple of days, Ubuntu 20.04 will be released. To insist to install hardware driver on two releases older distribution, just because the maintainer (AMD) has not had a chance to update the driver installation is not reasonable.
Please restore the original post because it provides a shortcut to install OpenCL drivers today, on Ubuntu other than 18.04 until AMD catches up with the Ubuntu release or decide to do the package release agnostic.