xbps-src: support temp overlays with bwrap

common/chroot-style/bwrap.sh

@@ -18,6 +18,14 @@ if [ -z "$MASTERDIR" -o -z "$DISTDIR" ]; then
 	exit 1
 fi
 
-exec bwrap --bind "$MASTERDIR" / --ro-bind "$DISTDIR" /void-packages \
-	 --dev /dev --tmpfs /tmp --proc /proc \
-	${HOSTDIR:+--bind "$HOSTDIR" /host} $EXTRA_ARGS "$@"
+if [ -z "$XBPS_TEMP_MASTERDIR" ]; then
+	exec bwrap --bind "$MASTERDIR" / \
+		--ro-bind "$DISTDIR" /void-packages \
+		--dev /dev --tmpfs /tmp --proc /proc \
+		${HOSTDIR:+--bind "$HOSTDIR" /host} ${EXTRA_ARGS} "$@"
+else
+	exec bwrap --overlay-src "$MASTERDIR" --tmp-overlay / \
+		--ro-bind "$DISTDIR" /void-packages \
+		--dev /dev --tmpfs /tmp --proc /proc \
+		${HOSTDIR:+--bind "$HOSTDIR" /host} ${EXTRA_ARGS} "$@"
+fi

common/chroot-style/uchroot.sh

@@ -33,4 +33,4 @@ if [ -z "$MASTERDIR" ] || [ -z "$DISTDIR" ]; then
 	exit 1
 fi
 
-exec xbps-uchroot $EXTRA_ARGS -b $DISTDIR:/void-packages ${HOSTDIR:+-b $HOSTDIR:/host} -- $MASTERDIR $CMD $@
+exec xbps-uchroot ${XBPS_TEMP_MASTERDIR:+-O} $EXTRA_ARGS -b $DISTDIR:/void-packages ${HOSTDIR:+-b $HOSTDIR:/host} -- $MASTERDIR $CMD "$@"

common/xbps-src/shutils/chroot.sh

@@ -179,6 +179,7 @@ chroot_handler() {
             SOURCE_DATE_EPOCH="$SOURCE_DATE_EPOCH" \
             XBPS_GIT_REVS="$XBPS_GIT_REVS" \
             XBPS_ALLOW_CHROOT_BREAKOUT="$XBPS_ALLOW_CHROOT_BREAKOUT" \
+            XBPS_TEMP_MASTERDIR="$XBPS_TEMP_MASTERDIR" \
             ${XBPS_ALT_REPOSITORY:+XBPS_ALT_REPOSITORY=$XBPS_ALT_REPOSITORY} \
             $XBPS_COMMONDIR/chroot-style/${XBPS_CHROOT_CMD:=uunshare}.sh \
             $XBPS_MASTERDIR $XBPS_DISTDIR "$XBPS_HOSTDIR" "$XBPS_CHROOT_CMD_ARGS" \

xbps-src

@@ -627,6 +627,14 @@ if [ "$2" ]; then
     XBPS_TARGET_PKG="${2##*/}"
 fi
 
+# A temporary masterdir requires xbps-uchroot(1) or bwrap(1).
+if [ -z "$IN_CHROOT" -a -n "$XBPS_TEMP_MASTERDIR" ]; then
+    case "$XBPS_CHROOT_CMD" in
+    uchroot|bwrap) ;;
+    *) XBPS_CHROOT_CMD="uchroot" ;;
+    esac
+fi
+
 # Check for CHROOT_READY and set up XBPS_ARCH environment var for xbps.
 chroot_check
 check_native_arch
@@ -719,12 +727,6 @@ for i in REPOSITORY DESTDIR BUILDDIR SRCDISTDIR; do
     unset val
 done
 
-# A temporary masterdir requires xbps-uchroot(1) and -O to use overlayfs
-# on tmpfs (available with xbps-0.45).
-if [ -z "$IN_CHROOT" -a -n "$XBPS_TEMP_MASTERDIR" ]; then
-    export XBPS_CHROOT_CMD="uchroot"
-    export XBPS_CHROOT_CMD_ARGS+=" -O"
-fi
 #
 # Sanitize PATH.
 #