[netmod] YANG 1.0 module uses a grouping from a 1.1 module and the grouping contains 1.1 XPath functions?

[Jernej Tuljak <[e-mail]>]

Hi,

there is at least one YANG 1.0 standard module that imports and uses 
groupings from a YANG 1.1 standard module and at least one such grouping 
contains must/when statements referencing XPath functions that are not 
available in 1.0 XPath context.

The modules I'm referring to are part of RFC8533 [1] and RFC8532 [2]. 
ietf-connectionless-oam-methods (a 1.0 module) uses cl-oam:tp-address 
from ietf-connectionless-oam (a 1.1 module), which calls 
"derived-from-or-self" in a when expression of a used node. These RFCs 
were published in April.

Our tools complain about "derived-from-or-self" not being defined in 
ietf-connectionless-oam-methods's XPath context:

[Error]; 
ietf-connectionless-oam-methods@2019-04-16:/cloam-methods:continuity-check/cloam-methods:input/cloam-methods:destination-tp/cloam-methods:mac-address/cloam-methods:when; 
XPath function "derived-from-or-self" is not defined in the XPath context

Is this correct? Or are XPath functions expected to be resolved 
statically, like types?

Jernej

[1] - https://tools.ietf.org/html/rfc8533
[2] -https://tools.ietf.org/html/rfc8532