Something is changed in the AMD APP SDK 3.0 for Linux
As I’ve been informed, the concerned team has decided to drop the support for APP SDK and hence, any related package on developer central might not be accessible anymore.
With AMDGPU-Pro and ROCm drivers, you don’t need a separate SDK because required libraries are shipped with the driver itself. And the headers to compile can be found with the package manager. For example on Debian based (like Ubuntu) distro:
$ sudo apt install opencl-headers
Where to find AMD APP SDK 3.0 for Linux? – AMD Support Forum – https://community.amd.com/thread/228059
Is AMD APP SDK 3.0 no longer available on AMD website? – XMR-Stak GitHub – https://github.com/fireice-uk/xmr-stak/issues/1511
AMD APP SDK – From Wikipedia, the free encyclopedia – https://en.wikipedia.org/wiki/AMD_APP_SDK