as per https://tools.ietf.org/html/rfc6020#section-7.1.4:

"All prefixes, including the prefix for the module itself MUST be unique within the module or submodule."

it appears that ODL considers prefixes to apply across a module and all of its submodules.

The specific example where we're hitting this is openconfig-isis and its submodule openconfig-isis-lsp.

openconfig-isis (revision 2017-05-15 in this instance, but also the latest revision 2017-07-26) imports ietf-inet-types as "inet"

openconfig-isis-lsp (again in both these revisions) imports openconfig-inet-types as "inet".

this results in ODL being unable to mount the device.

Logs attached.