googling 'use 5.010' produced the docs for use saying

In the peculiar use VERSION form, ... A fatal error is produced if VERSION is greater than the version of the current Perl interpreter; Perl will not attempt to parse the rest of the file.

...

Also, if the specified perl version is greater than or equal to 5.9.5, use VERSION will also load the feature pragma and enable all features available in the requested version. See feature.

state is one of these features! (but better avoid it ATM as it has weird side effects)