Because it is a huge PITA to keep updating things and by having the versions specified explicitly on the Vagrantfile will ensure that developers won't have trouble when recreating a VM that ends up with a different version of Ruby (for example) and things end up falling apart.
Because it is a huge PITA to keep updating things and by having the versions specified explicitly on the Vagrantfile will ensure that developers won't have trouble when recreating a VM that ends up with a different version of Ruby (for example) and things end up falling apart.