pkg/59856: Incorrect Boost::headers.INTERFACE_INCLUDE_DIRECTORIES when using CMake

>Number:         59856
>Category:       pkg
>Synopsis:       Incorrect Boost::headers.INTERFACE_INCLUDE_DIRECTORIES when using CMake
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Dec 23 20:25:00 +0000 2025
>Originator:     Hennadii Stepanov
>Release:        pkgsrc-2025Q4
>Organization:
https://github.com/bitcoin-core
>Environment:
NetBSD netbsd-full 10.1 NetBSD 10.1 (GENERIC) #0: Mon Dec 16 13:08:11 UTC 2024  [email protected]:/usr/src/sys/arch/amd64/compile/GENERIC amd6
>Description:
The CMake package configuration files installed by the `meta-pkgs/boost` package specify the `/usr` include directory instead of the correct `/usr/pkg/include` path.

This makes it problematic to use this package in other CMake-based projects.
>How-To-Repeat:
$ pkgin install boost
$ cat CMakeLists.txt
cmake_minimum_required(VERSION 3.31)
project(BoostCMakeIncludesBug)
find_package(Boost REQUIRED CONFIG)
include(CMakePrintHelpers)
cmake_print_properties(TARGETS Boost::headers
  PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
)
$ cmake .
...
-- 
 Properties for TARGET Boost::headers:
   Boost::headers.INTERFACE_INCLUDE_DIRECTORIES = "/usr"
...
>Fix: