Can't install: Unsatisfiable requirements

[droodman]

(@v1.9) pkg> add KernelEstimator
   Resolving package versions...
ERROR: Unsatisfiable requirements detected for package CUDA [052768ef]:
 CUDA [052768ef] log:
 ├─possible versions are: 0.1.0-4.3.2 or uninstalled
 ├─restricted to versions * by an explicit requirement, leaving only versions: 0.1.0-4.3.2
 ├─restricted by compatibility requirements with SpecialFunctions [276daf66] to versions: 0.1.0-2.6.3 or uninstalled, leaving only versions: 0.1.0-2.6.3
 │ └─SpecialFunctions [276daf66] log:
 │   ├─possible versions are: 0.7.0-2.2.0 or uninstalled
 │   ├─restricted to versions * by an explicit requirement, leaving only versions: 0.7.0-2.2.0
 │   └─restricted by compatibility requirements with KernelEstimator [857edff2] to versions: 0.7.0-0.10.3
 │     └─KernelEstimator [857edff2] log:
 │       ├─possible versions are: 0.3.3 or uninstalled
 │       └─restricted to versions * by an explicit requirement, leaving only versions: 0.3.3
 ├─restricted by julia compatibility requirements to versions: [2.3.0, 2.5.0-4.3.2] or uninstalled, leaving only versions: [2.3.0, 2.5.0-2.6.3]
 └─restricted by compatibility requirements with LLVM [929cbde3] to versions: 3.3.3-4.3.2 or uninstalled — no versions left
   └─LLVM [929cbde3] log:
     ├─possible versions are: 0.9.0-5.2.0 or uninstalled
     ├─restricted by compatibility requirements with CUDA [052768ef] to versions: 1.5.0-5.2.0
     │ └─CUDA [052768ef] log: see above
     └─restricted by julia compatibility requirements to versions: 4.0.0-5.2.0 or uninstalled, leaving only versions: 4.0.0-5.2.0
``