The target_link_libraries command records the PRIVATE dependencies of a
STATIC library in INTERFACE_LINK_LIBRARIES as "$<LINK_ONLY:dep>".  This
hides the target name from export namespacing logic inside a generator
expression.  When user-written generator expressions reference a target
name they must put it inside a "$<TARGET_NAME:dep>" expression to allow
the export logic to rename the target.  In the case that the private
dependency is not already a generator expression, target_link_libraries
must use "$<LINK_ONLY:$<TARGET_NAME:dep>>" to allow the export logic to
rename the target.

Reported-by: Tamás Kenéz <tamas.kenez@gmail.com>