More suggestive error for uninitialized parameters

[rolandgvc]

Hi guys! While playing with the Linen API for transfer learning, I've found the AssertionError: Need PRNG for "params" error quite confusing when trying to match the parameter namings to the model's layers. I was wondering if we could have a more explicit error when certain variables haven't been (or cannot be) initialized.

[avital]

Hi Roland! I filed #489, does this cover the situation that you've encountered?

[rolandgvc]

Hi Avital, yes, that's great! Thank you.