The type or namespace name 'BurstCompile' could not be found (are you missing a using directive or an assembly reference?)

I have written a job that uses the Burst Compiler. Everything was fine until I moved it into a folder containing an Assembly Definition. At which point, it stopped compiling with a message about the unknown [BurstCompiler] attribute.

I am using Unity 2019.2.18f and Burst Compiler 1.2.0 preview-12.

Does anyone know if Assembly Definitions are supported by Burst? And if so, what you need to do to get them to work?

You need to ad Unity.Burst to the asmdef’s assembly definition references.