no method matching unsafe_string(::Ptr{Void})

[cmey]

julia> Pkg.test("OpenCL")
INFO: Testing OpenCL
Test Summary:   | Pass  Total
OpenCL.Platform |   13     13
Test Summary:  | Pass  Total
OpenCL.Context |   26     26
Test Summary: | Pass  Total
OpenCL.Device |  122    122
WARNING: Platform Apple does not seem to suport out of order queues:
CLError(code=-30, CL_INVALID_VALUE)
ERROR (unhandled task failure): MethodError: no method matching unsafe_string(::Ptr{Void})
Closest candidates are:
  unsafe_string(::Cstring) at c.jl:79
  unsafe_string(::Union{Ptr{Int8}, Ptr{UInt8}}) at strings/string.jl:39
  unsafe_string(::Union{Ptr{Int8}, Ptr{UInt8}}, ::Integer) at strings/string.jl:35
Stacktrace:
 [1] macro expansion at /Users/cmey/.julia/v0.6/OpenCL/src/context.jl:95 [inlined]
 [2] (::OpenCL.cl.##43#44)() at ./task.jl:335
Test Summary:   | Pass  Total
OpenCL.CmdQueue |   61     61

julia> Pkg.status("OpenCL")
 - OpenCL                        0.5.2

julia> versioninfo()
Julia Version 0.6.0
Commit 903644385b (2017-06-19 13:05 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i7-4980HQ CPU @ 2.80GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, haswell)