Hi @JKempster,
it’s pretty clear where HistFactory calls the interpreter: in any call to RooWorkspace::factory(), because the parsing of the factory language and creating the corresponding object on-the-fly must be done with the JIT.
I suggest to fix this by avoiding all calls to RooWorkspace::factory() in HistFactory:
Once this PR is merged, you should not see your problems anymore with ROOT master.
How important is it for you that this works also in the 6.30 series? Then I would also have to backport the fix to the 6.30 branch in order to appear in the 6.30.04 release. But if you don’t care about waiting for 6.32.00, then I don’t need to do that (backports always have a slight risk of breaking something).
Cheers,
Jonas