@henryiii, this OMP test is failing, as far as I understand, due to a change in the latest root version. Would you know how to fix it? I tried declaring an instance of MnPrint locally, but it didn't work.

I think this was a change in root-project/root#6705. I'll try to look through that soon and see what changed. @HDembinski, does iMinuit provide a public pybind11 API for integrating custom classes? It would be nicer if this could simply register iMinuit classes instead of wrapping Minuit separately.

Yes, it looks like that patch contains a breaking change - the static functions Level and SetLevel were renamed to SetGlobalLevel and GlobalLevel, and MnPrint is now a class, which means we either have to drop support for < 6.24, or add versions checks and multiple versions of these parts. One could argue we likely are really using the easy but wrong thing by setting the global print level, as setting the level on the specific object is better; so maybe I'll try to use that in a couple of places first.

I think this was a change in root-project/root#6705. I'll try to look through that soon and see what changed. @HDembinski, does iMinuit provide a public pybind11 API for integrating custom classes? It would be nicer if this could simply register iMinuit classes instead of wrapping Minuit separately.

Hi, I am not sure what you mean. The pybind11 wrapper for Minuit2 in iminuit is mostly a thin wrapper around the C++ code, while iminuit is built in Python on that foundation. There is one hybrid class, FCN, which overrides methods in FCNBase to call Python implementations.

I improved the Printing in Minuit2 somewhat, but this is probably not the last change. The print level is still a global variable which causes problems with parallelization.