ec['parallel'] currently doubles as an EC option and as the storage for the calculated parallelism set by the EasyBlock.
This makes it hard to reason about especially as maxparallel has pretty much the same effect. Also changes to ec['parallel'] done by e.g. easyblocks (or the set_parallel method) are not reflected by the template
Solution: Introduce a property which on write updates the template and some magic to mirror the effect of the now deprecated ec['parallel']
Additional change I'd like to do: Treat
parallel = False (legacy) as
maxparallel =1 so
cfg.parallel is always a number
See https://github.com/easybuilders/easybuild-framework/pull/3811#issuecomment-911819520 for the motivation