CUDA missing libGL.so libGLU.so and libX11.so

Linux Mint is not an officially supported distro for CUDA. So it's possible that the CUDA install method (the driver install portion, in this case) you are using is placing the necessary GL libraries in a place that the makefile is not equipped to find.

If you study the findgllib.mk makefile "helper" file in the build directory, I suspect a debian based distribution would follow the UBUNTU path in that .mk file. For the non-ppc and non-arm branches, you will find definitions like this:

ifeq ("$(UBUNTU)","0")
  ifeq ...
  ...
  else
    GLPATH    ?= /usr/lib/$(UBUNTU_PKG_NAME)
    GLLINK    ?= -L/usr/lib/$(UBUNTU_PKG_NAME)
    DFLT_PATH ?= /usr/lib

Given that:

1. You have stated that the GL libraries seemed to be installed.
2. You've symlinked those libraries into the /usr/lib directory
3. The GLPATH definition in the .mk file is a "non-override" definition (i.e. ?=)

we can "override" or replace the GLPATH definition concocted by the makefile with the "known good" one of /usr/lib with:

GLPATH=/usr/lib

prepended to your make command.