Unreachable reached in Julia v1.3/1.4

[schillic]

At least on my system the following test code crashes with a Julia bug (Unreachable reached, signal (4): Illegal instruction).

https://github.com/JuliaReach/Reachability.jl/blob/6fb396dbb6f2780362e0960978492d845738517a/test/ReachSets/unit_discretization.jl#L151-L161

I tried to debug it and apparently there is a problem when we create the result system:

https://github.com/JuliaReach/Reachability.jl/blob/6fb396dbb6f2780362e0960978492d845738517a/src/ReachSets/discretize.jl#L832

The system itself can be created without problems if you outsorce this line to a new helper function. But for some reason the compiler seems surprised that it can return that result and then crashes.