+: ${VPP_BUILD_USER:=$(whoami)}
+: ${VPP_BUILD_HOST:=$(hostname)}
+DATE_FMT="+%Y-%m-%dT%H:%M:%S"
+SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:-$(date +%s)}"
+VPP_BUILD_DATE=$(date -u -d "@$SOURCE_DATE_EPOCH" "$DATE_FMT" 2>/dev/null || date -u -r "$SOURCE_DATE_EPOCH" "$DATE_FMT" 2>/dev/null || date -u "$DATE_FMT")