Problem first started with a stall when disengaging clutch. Now it won't start. Battery is strong, no previous starting problems. Now start attempt makes fast-turning but "gutless" whine; turnover or ignition. Could this be solenoid?

Engine is relatively new replaced in last few yrs, with <100,000 km's no on it.

I mean.. no turnover or ignition...

If the starter motor does not engage the flywheel, the starter motor's overriding clutch is shot. If this is the situation, replace the starter motor.

If the starter motor works properly, check the timing belt. Remove the oil filler cap, have someone crank the engine, and observe whether the camshaft rotates. If it doesn't the timing belt snapped.