build: prevent build on pkg version mismatches #249

If the build system version aqcuired by FreeBSD packages is newer
chances are that the database result is going to be unmanageable
for the version we use at the moment.

build/common.sh

@@ -720,6 +720,13 @@ check_packages()
 	local SELF=${1}
 	SKIP=${2}
 
+	PKG_WANT=$(make -C ${PORTSDIR}/ports-mgmt/pkg -v PORTVERSION | cut -d. -f 1-2)
+	PKG_HAVE=$(pkg -v | cut -d. -f 1-2)
+	if [ "${PKG_WANT}" != "${PKG_HAVE}" ]; then
+		echo "Installed pkg version '${PKG_HAVE}' does not match required version '${PKG_WANT}'" >&2
+		exit 1
+	fi
+
 	PACKAGESET=$(find_set packages)
 
 	if [ -z "${SELF}" -o -z "${PACKAGESET}" -o -n "${SKIP}" ]; then