When I ]build Sundials, I get:
(v1.2) pkg> build Sundials
Building Sundials → `D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\build.log`
┌ Error: Error building `Sundials`:
│ ┌ Warning: On Windows, creating file symlinks requires Administrator privileges
│ └ @ Base.Filesystem file.jl:797
│ ┌ Warning: platform_key() is deprecated, use platform_key_abi() from now on
│ │ caller = ip:0x0
│ └ @ Core :-1
│ [ Info: Downloading https://github.com/JuliaDiffEq/SundialsBuilder/releases/download/sundials-3.1.1.6/Sundials.v1.0.0.x86_64-w64-mingw32.tar.gz to D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\usr\downloads\Sundials.v1.0.0.x86_64-w64-mingw32.tar.gz...
│ ERROR: LoadError: Could not download https://github.com/JuliaDiffEq/SundialsBuilder/releases/download/sundials-3.1.1.6/Sundials.v1.0.0.x86_64-w64-mingw32.tar.gz to D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\usr\downloads\Sundials.v1.0.0.x86_64-w64-mingw32.tar.gz:
│ ErrorException("")
│ Stacktrace:
│ [1] error(::String) at .\error.jl:33
│ [2] #download#93(::Bool, ::typeof(BinaryProvider.download), ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:498
│ [3] #download at .\none:0 [inlined]
│ [4] #download_verify#94(::Bool, ::Bool, ::Bool, ::typeof(download_verify), ::String, ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:567
│ [5] #download_verify at .\tuple.jl:0 [inlined]
│ [6] #install#133(::Prefix, ::String, ::Bool, ::Bool, ::Bool, ::typeof(install), ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\Prefix.jl:314
│ [7] (::getfield(BinaryProvider, Symbol("#kw##install")))(::NamedTuple{(:prefix, :force, :verbose),Tuple{Prefix,Bool,Bool}}, ::typeof(install), ::String, ::String) at .\tuple.jl:0
│ [8] top-level scope at D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\build.jl:53
│ [9] include at .\boot.jl:328 [inlined]
│ [10] include_relative(::Module, ::String) at .\loading.jl:1094
│ [11] include(::Module, ::String) at .\Base.jl:31
│ [12] include(::String) at .\client.jl:431
│ [13] top-level scope at none:5
│ in expression starting at D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\build.jl:49
│ caused by [exception 2]
│
│ Stacktrace:
│ [1] error() at .\error.jl:42
│ [2] #download#93(::Bool, ::typeof(BinaryProvider.download), ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:492
│ [3] #download at .\none:0 [inlined]
│ [4] #download_verify#94(::Bool, ::Bool, ::Bool, ::typeof(download_verify), ::String, ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:567
│ [5] #download_verify at .\tuple.jl:0 [inlined]
│ [6] #install#133(::Prefix, ::String, ::Bool, ::Bool, ::Bool, ::typeof(install), ::String, ::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\Prefix.jl:314
│ [7] (::getfield(BinaryProvider, Symbol("#kw##install")))(::NamedTuple{(:prefix, :force, :verbose),Tuple{Prefix,Bool,Bool}}, ::typeof(install), ::String, ::String) at .\tuple.jl:0
│ [8] top-level scope at D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\build.jl:53
│ [9] include at .\boot.jl:328 [inlined]
│ [10] include_relative(::Module, ::String) at .\loading.jl:1094
│ [11] include(::Module, ::String) at .\Base.jl:31
│ [12] include(::String) at .\client.jl:431
│ [13] top-level scope at none:5
│ caused by [exception 1]
│ IOError: symlink: operation not permitted (EPERM)
│ Stacktrace:
│ [1] uv_error at .\libuv.jl:90 [inlined]
│ [2] symlink(::String, ::String) at .\file.jl:800
│ [3] probe_symlink_creation(::String) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:121
│ [4] #probe_platform_engines!#30(::Bool, ::typeof(BinaryProvider.probe_platform_engines!)) at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:175
│ [5] probe_platform_engines! at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\PlatformEngines.jl:169 [inlined]
│ [6] __init__() at D:\Users\jdiegelm\.julia\packages\BinaryProvider\TcAwt\src\BinaryProvider.jl:28
│ [7] _include_from_serialized(::String, ::Array{Any,1}) at .\loading.jl:685
│ [8] _require_search_from_serialized(::Base.PkgId, ::String) at .\loading.jl:765
│ [9] _require(::Base.PkgId) at .\loading.jl:990
│ [10] require(::Base.PkgId) at .\loading.jl:911
│ [11] require(::Module, ::Symbol) at .\loading.jl:906
│ [12] include at .\boot.jl:328 [inlined]
│ [13] include_relative(::Module, ::String) at .\loading.jl:1094
│ [14] include(::Module, ::String) at .\Base.jl:31
│ [15] include(::String) at .\client.jl:431
│ [16] top-level scope at none:5
│ Exception setting "SecurityProtocol": "Cannot convert null to type "System.Net.SecurityProtocolType" due to invalid enumeration values. Speci
│ fy one of the following enumeration values and try again. The possible enumeration values are "Ssl3, Tls"."
│ At line:1 char:35
│ + [System.Net.ServicePointManager]:: <<<< SecurityProtocol =
│ + CategoryInfo : InvalidOperation: (:) [], RuntimeException
│ + FullyQualifiedErrorId : PropertyAssignmentException
│
│ Exception calling "DownloadFile" with "2" argument(s): "The underlying connection was closed: An unexpected error occurred on a send."
│ At line:5 char:24
│ + $webclient.DownloadFile <<<< ("https://github.com/JuliaDiffEq/SundialsBuilder/releases/download/sundials-3.1.1.6/Sundials.v1.0.0.x86_64-w64
│ -mingw32.tar.gz", "D:\Users\jdiegelm\.julia\packages\Sundials\CRi5j\deps\usr\downloads\Sundials.v1.0.0.x86_64-w64-mingw32.tar.gz")
│ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException
│ + FullyQualifiedErrorId : DotNetMethodException