$ perl5.10.0 -e 'use Foo v0.1_1' Foo version v0.1_1 required--this is only version v0.0_1 at -e line 1. BEGIN failed--compilation aborted at -e line 1. $ perl5.8.0 -e 'use Foo v0.1_1' Foo version v0.1.1 required--this is only version v0.0.1 at -e line 1. BEGIN failed--compilation aborted at -e line 1. $ perl5.6.2 -e 'use Foo v0.1_1' Foo version 0.011 required--this is only version 0 at -e line 1. BEGIN failed--compilation aborted at -e line 1.