:use
The arguments to :use set the packages that the package named by package-name will inherit from. If :use is not supplied, it defaults to the same implementation-dependent value as the :use argument to make-package.
To ensure that no packages are used, you have to do something like:
This DEFPACKAGE form generates potentially noncoforming code for the various services:
https://github.com/pokepay/aws-sdk-lisp/blob/7d3d0d2050f98d95aa9bed019fde3e78d9de7cb3/generator/service.lisp#L21-L25
As the standard says:
To ensure that no packages are used, you have to do something like:
http://www.lispworks.com/documentation/HyperSpec/Body/m_defpkg.htm#defpackage
This actually causes issues on lispworks.