Platform not found

[ameresj]

When building julia Version 0.6.0-dev.1378 on ubuntu 16.04, I can successfully use access OpenCL.

julia> using OpenCL
julia> platform=cl.platforms()
igdrcl: using XCB-DRI2 authentication...
1-element Array{OpenCL.cl.Platform,1}:
 OpenCL.Platform('Intel(R) OpenCL' @0x000000000318a460)
julia> cl.devices(platform[1])
2-element Array{OpenCL.cl.Device,1}:
 OpenCL.Device(Intel(R) HD Graphics on Intel(R) OpenCL @0x0000000002979820)                    
 OpenCL.Device(Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz on Intel(R) OpenCL @0x00000000031b88d8)

Nevertheless for the stable and also nightly build binaries from the Ubuntu repository it doesn't even find the platform. For example julia version 0.6.0-dev gives me:

ERROR: LoadError: CLError(code=-1001, CL_PLATFORM_NOT_FOUND_KHR)
 in macro expansion at /home/ameresj/.julia/v0.6/OpenCL/src/macros.jl:6 [inlined]
 in platforms() at /home/ameresj/.julia/v0.6/OpenCL/src/platform.jl:20
 in create_some_context() at /home/ameresj/.julia/v0.6/OpenCL/src/context.jl:235
 in create_compute_context() at /home/ameresj/.julia/v0.6/OpenCL/src/util.jl:2
 in include_from_node1(::String) at ./loading.jl:532
 in include(::String) at ./sysimg.jl:14
 in process_options(::Base.JLOptions) at ./client.jl:271
 in _start() at ./client.jl:335

Python with pyopencl works out of the box, so it has to be something julia specific that I am missing here. Probably some library path is redefined. What is a good point to start looking?

[vchuravy]

I am not quite sure how to debug this from afar. Make sure that the same OpenCL library is loaded (see https://github.com/JuliaGPU/OpenCL.jl/blob/master/src/api.jl#L5-L8) and that you onnly have one OpenCL library installed. It might be that you have two on your load path. We get the platforms from the OpenCL library and there should be no difference between versions or between Julia and Python