Patch developed inhouse, submitted upstream.
Details at
https://sourceforge.net/p/net-snmp/bugs/2940/
--- net-snmp-5.9.4/net-snmp-create-v3-user.in.orig
+++ net-snmp-5.9.4/net-snmp-create-v3-user.in
@@ -122,7 +122,7 @@
 if test "x$xpassphrase" = "x" ; then
     line="createUser $user $Aalgorithm \"$apassphrase\" $Xalgorithm"
 else
-    line="createUser $user $Aalgorithm \"$apassphrase\" $Xalgorithm \"$xpassphrase\""
+    line="createUser $user $Aalgorithm \"$apassphrase\" $Xalgorithm $xpassphrase
 fi
 echo "adding the following line to $outfile:"
 echo "   $line"