Fatal error on uninstall: BaseFieldDefinition could not be converted to string

Committed and pushed to 8.x-4.x.

Thanks for the bug report.

I couldn't reproduce this at first until I traced it back to having devel installed. Turns out the devel calls set_error_handler('backtrace_error_handler'); which then handles this error and simply logs it to watchdog, because after all it is a *Recoverable* fatal error. Disabling devel results in the fatal printed to screen and the uninstall failing.

So my guess as to why this is happening is that calling array_diff_assoc() on $entity_manager->getBaseFieldDefinitions('node', 'webform') causes a string conversion on at least one of the values (a magic __toString() call?). The odd thing is it only effects $entity_manager->getBaseFieldDefinitions() and not $entity_manager->getFieldDefinitions. Odd. Thankfully once that all made sense it was just a matter of calling array_diff_key() which just looks at the keys rather than array_diff_assoc().

Committed and pushed #5 to 8.x-4.x.

Good catch, thanks!