mtree violation

[macports at parvis.nl]

I'm trying to local install jdupes with my own test fixes, but i cannot destroot/activate due to more violation.

how can i - without patching the Makefile, specify /opt/local as destination?

logextract:
-----------
# port install jdupes
--->  Fetching distfiles for jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from https://distfiles.macports.org/jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from http://lil.fr.distfiles.macports.org/jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from http://mse.uk.distfiles.macports.org/sites/distfiles.macports.org/jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from http://nue.de.distfiles.macports.org/jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from http://fco.it.distfiles.macports.org/mirrors/macports-distfiles/jdupes
--->  Attempting to fetch jdupes-1.9.tar.gz from https://github.com/jbruchon/jdupes/tarball/v1.9
--->  Verifying checksums for jdupes
--->  Extracting jdupes
--->  Configuring jdupes
--->  Building jdupes
--->  Staging jdupes into destroot
Warning: violation by /usr
Warning: jdupes violates the layout of the ports-filesystems!
Warning: Please fix or indicate this misbehavior (if it is intended), it will be an error in future releases!
--->  Installing jdupes @1.9_0
--->  Activating jdupes @1.9_0
Error: Failed to activate jdupes: error renaming "/opt/local/var/macports/software/jdupes/mpextract6qgNCRhA/usr/bin/jdupes" to "/usr/bin/jdupes": not owner
Error: See /opt/local/var/macports/logs/_Users_paul_Develop_macports_jdupes_sysutils_jdupes/jdupes/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port jdupes failed

Portfile:
---------
# -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4
PortSystem          1.0
PortGroup           github 1.0
github.setup        jbruchon jdupes 1.9 v
categories          sysutils
platforms           darwin
license             MIT
maintainers         nomaintainer
description         A powerful duplicate file finder and an enhanced fork of 'fdupes'.
long_description    ${description}
checksums           rmd160 abe9c903f401a48e8fc13c7631947dc6ba534856 \
                    sha256 689ce2f560b8ec015fda23f8c9f04738321d90293118165f9b0d96c97630d6f2
use_configure        no

fragment of original Makefile:
------------------------------
# PREFIX determines where files will be installed. Common examples
# include "/usr" or "/usr/local".
PREFIX = /usr
(...)
# PROGRAM_NAME determines the installation name and manual page name
PROGRAM_NAME = jdupes
# BIN_DIR indicates directory where program is to be installed.
# Suggested value is "$(PREFIX)/bin"
BIN_DIR = $(PREFIX)/bin
# MAN_DIR indicates directory where the jdupes man page is to be
# installed. Suggested value is "$(PREFIX)/man/man1"
MAN_BASE_DIR = $(PREFIX)/share/man
MAN_DIR = $(MAN_BASE_DIR)/man1
MAN_EXT = 1
(...)
install: jdupes installdirs
  $(INSTALL_PROGRAM)  $(PROGRAM_NAME)   $(DESTDIR)$(BIN_DIR)/$(PROGRAM_NAME)
  $(INSTALL_DATA)   $(PROGRAM_NAME).1 $(DESTDIR)$(MAN_DIR)/$(PROGRAM_NAME).$(MAN_EXT)
(...)

thanks,
pdv.