iOS Shader.WarmupAllShaders() crashes with SpeedTree shaders

I'm using SpeedTree in my project, when a shader is used for the first time it hiccups, causing massive lag during gameplay. So i need to warmup the shaders/preload them.

If i call Shader.WarmupAllShaders() or adding shader variants into Preloaded Shaders in the Graphics settings it crashes. I get a log showing the code for the shaders themselves with equality warnings.

Has anyone come across this issue? I am running Unity 5.0.1f1 and building to an iPhone 5s running iOS 8.3 and building onto the device using Xcode 6.3.1

Here is an example of the Shader compiler warnings:

 Compilation succeeded with: 
 
 program_source:275:19: warning: equality comparison with extraneous parentheses
     if ((tmpvar_9 == (half)5.0)) {
          ~~~~~~~~~^~~~~~~~~~~~
 program_source:275:19: note: remove extraneous parentheses around the comparison to silence this warning
     if ((tmpvar_9 == (half)5.0)) {
         ~         ^           ~
 program_source:275:19: note: use '=' to turn this equality comparison into an assignment
     if ((tmpvar_9 == (half)5.0)) {
                   ^~