-exec has been around since 2012 is cleaner and shorter, I don't see why xargs(1) should be used for such simple cases. Besides that don't walk the tree twice.
Index: include/Makefile =================================================================== RCS file: /cvs/src/include/Makefile,v retrieving revision 1.219 diff -u -p -r1.219 Makefile --- include/Makefile 17 Apr 2017 15:53:21 -0000 1.219 +++ include/Makefile 3 Jun 2017 12:48:19 -0000 @@ -100,10 +100,9 @@ includes: cd ${.CURDIR}/$$i && ${RUN_MAKE}; \ done chown -RP ${BINOWN}:${BINGRP} ${DESTDIR}/usr/include - find ${DESTDIR}/usr/include -type f -print0 | \ - xargs -0r chmod a=r - find ${DESTDIR}/usr/include \( -type d -o -type l \) -print0 | \ - xargs -0r chmod -h u=rwx,go=rx + find ${DESTDIR}/usr/include \ + \( -type f -exec chmod a=r {} + \) -o \ + \( \( -type d -o -type l \) -exec chmod -h u=rwx,go=rx {} + \) copies: @echo copies: ${LDIRS} Index: share/zoneinfo/Makefile =================================================================== RCS file: /cvs/src/share/zoneinfo/Makefile,v retrieving revision 1.11 diff -u -p -r1.11 Makefile --- share/zoneinfo/Makefile 24 Nov 2016 14:38:30 -0000 1.11 +++ share/zoneinfo/Makefile 3 Jun 2017 12:48:19 -0000 @@ -81,8 +81,9 @@ realinstall: ${DATA} ${REDO} ${YEARISTYP (cd ${.CURDIR}/datfiles; \ ${ZIC} -y ${YEARISTYPECOPY} -d ${TZDIR} -p ${POSIXRULES}) chown -R ${BINOWN}:${BINGRP} ${TZDIR} - find ${TZDIR} -type f -print0 | xargs -0r chmod a=r - find ${TZDIR} -type d -print0 | xargs -0r chmod a=rx + find ${TZDIR} \ + \( -type f -exec chmod a=r {} + \) -o \ + \( -type d -exec chmod a=rx {} + \) ${INSTALL} -c -o root -g bin -m 644 ${.CURDIR}/datfiles/iso3166.tab \ ${DESTDIR}/usr/share/misc ${INSTALL} -c -o root -g bin -m 644 ${.CURDIR}/datfiles/zone.tab \