it has been deprecated in libosmocore.git 2.5 years ago:
commit 7e0686c6b4b456ec4e6e15689694b1bcf96c301f
Author: Neels Hofmeyr <neels@hofmeyr.de>
Date: Mon Sep 10 20:58:52 2018 +0200
Change-Id: Ia6946fae497319a894d4e664ac8642340620822e
To support Iu tests, start osmo-stp when testing.
Depends-on: I66069e31c30d33934ad57cc2b8794f56ffd5c7d6 (osmo-ttcn3-hacks)
Change-Id: I4d6aef98832202652c5fe254105728430ba77119