Index: Mk/Scripts/qa.sh
===================================================================
--- Mk/Scripts/qa.sh
+++ Mk/Scripts/qa.sh
@@ -2,8 +2,8 @@
 # MAINTAINER: portmgr@FreeBSD.org
 # $FreeBSD$
 
-if [ -z "${STAGEDIR}" -o -z "${PREFIX}" -o -z "${LOCALBASE}" ]; then
-	echo "STAGEDIR, PREFIX, LOCALBASE required in environment." >&2
+if [ -z "${STAGEDIR}" -o -z "${PREFIX}" -o -z "${LOCALBASE}" -o -z "${REWARNFILE}" ]; then
+	echo "STAGEDIR, PREFIX, LOCALBASE, REWARNFILE required in environment." >&2
 	exit 1
 fi
 
@@ -1006,10 +1006,18 @@
 	return 0
 }
 
+reinplace()
+{
+	if [ -f ${REWARNFILE} ]; then
+		warn "Possible REINPLACE_CMD issues"
+		cat ${REWARNFILE}
+	fi
+}
+
 checks="shebang symlinks paths stripped desktopfileutils sharedmimeinfo"
 checks="$checks suidfiles libtool libperl prefixvar baselibs terminfo"
 checks="$checks proxydeps sonames perlcore no_arch gemdeps gemfiledeps flavors"
-checks="$checks license depends_blacklist pkgmessage"
+checks="$checks license depends_blacklist pkgmessage reinplace"
 
 ret=0
 cd ${STAGEDIR} || exit 1
Index: Mk/bsd.port.mk
===================================================================
--- Mk/bsd.port.mk
+++ Mk/bsd.port.mk
@@ -1617,6 +1617,9 @@
 				PREFIX=${PREFIX} \
 				LINUXBASE=${LINUXBASE} \
 				LOCALBASE=${LOCALBASE} \
+				REWARNFILE=${WRKDIR}/reinplace_warnings.txt \
+				WRKDIR=${WRKDIR} \
+				WRKSRC=${WRKSRC} \
 				"STRIP=${STRIP}" \
 				TMPPLIST=${TMPPLIST} \
 				CURDIR='${.CURDIR}' \
@@ -2005,7 +2008,11 @@
 
 # Macro for doing in-place file editing using regexps
 REINPLACE_ARGS?=	-i.bak
+.if defined(DEVELOPER)
+REINPLACE_CMD?=	${SETENV} REWARNFILE=${WRKDIR}/reinplace_warnings.txt ${PORTSDIR}/Tools/scripts/sed_checked.sh
+.else
 REINPLACE_CMD?=	${SED} ${REINPLACE_ARGS}
+.endif
 
 # Names of cookies used to skip already completed stages
 EXTRACT_COOKIE?=	${WRKDIR}/.extract_done.${PORTNAME}.${PREFIX:S/\//_/g}
Index: Tools/scripts/sed_checked.sh
===================================================================
--- /dev/null
+++ Tools/scripts/sed_checked.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+#set -x
+
+/usr/bin/sed -i.bak "$@"
+for x in "${@}" ; do
+    if [ -f "${x}" ]; then
+        cmp "${x}" "${x}".bak > /dev/null 2>&1
+        if [ $? -ne 1 ]; then
+            if [ ! -z "${REWARNFILE}" ]; then
+                echo sed failed: backup file same as original: ${x} >> ${REWARNFILE}
+            fi
+        fi
+    fi
+done