`ode.u0` is overwritten

[MarcoArtiano]

When running the code, we overwrite somehow ode.u0, so that if we just run the solve call after a first include, the simulation will rather crash or give wrong result. To avoid that, we are forced to recall the ode constructor, before running the solve call.

[vchuravy]

Is this for all time integrators or just some of them.

[MarcoArtiano]

It seems that all of them are affected.

[ranocha]

SciML has an alias_u0 keyword argument for this - or at least had one and may have generalized it to some more general alias specifier.

[vchuravy]

https://docs.sciml.ai/SciMLBase/dev/interfaces/Problems/nothing/SciMLBase/stable/interfaces/Problems/#Aliasing-Specification

Need to figure out how we are supposed to handle that internally

[ranocha]

https://docs.sciml.ai/SciMLBase/dev/interfaces/Problems/#SciMLBase.ODEAliasSpecifier

If the part alias_u0 is false, we need to copy(u0) to get the initial u we can overwrite during the simulation.

[MarcoArtiano]

I've been testing a bit to find the source of the problem, and ode.u0 is being changed only in the callbacks call. It is still not clear to me why that happens, since Trixi.jl has similar structure and there it doesn't happen.