import fails without ROL

[icepack]

import fails without ROL

[danshapero]

Oof yea that's on me. Building Florian's Python wrappers for ROL requires patchelf, so if I just add ROL as a dependency then I don't think that's going to fix the problem upstream.

[JDBetteridge]

Could this be handled as a conditional import instead?

import pyadjoint.optimization.rol_solver
try:
    x = pyadjoint.optimization.rol_solver.ROLObjective
    some_flag_that_turns_ROL_stuff_on = True
except AttributeError:
    some_flag_that_turns_ROL_stuff_on = False

pyadjoint doesn't raise an import error if ROL isn't installed I notice