<p>May be that because <code>mod_register</code> for <code>systemdops_mod</code> is empty function and not make call of <code>r_event_register_cb</code>?<br>
<a href="https://github.com/kamailio/kamailio/blob/master/src/modules/systemdops/systemdops_mod.c#L69-L72">https://github.com/kamailio/kamailio/blob/master/src/modules/systemdops/systemdops_mod.c#L69-L72</a></p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/kamailio/kamailio/issues/2139?email_source=notifications&email_token=ABO7UZIWWJOIWVF42NICRLDQU6G3LA5CNFSM4JPDHWL2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEE43Z2I#issuecomment-557432041">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/ABO7UZLYNTWZDSO5GHSYSSLQU6G3LANCNFSM4JPDHWLQ">unsubscribe</a>.<img src="https://github.com/notifications/beacon/ABO7UZO7OPFYNBF4J3LUXLLQU6G3LA5CNFSM4JPDHWL2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEE43Z2I.gif" height="1" width="1" alt="" /></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/kamailio/kamailio/issues/2139?email_source=notifications\u0026email_token=ABO7UZIWWJOIWVF42NICRLDQU6G3LA5CNFSM4JPDHWL2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEE43Z2I#issuecomment-557432041",
"url": "https://github.com/kamailio/kamailio/issues/2139?email_source=notifications\u0026email_token=ABO7UZIWWJOIWVF42NICRLDQU6G3LA5CNFSM4JPDHWL2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEE43Z2I#issuecomment-557432041",
"name": "View Issue"
},
"description": "View this Issue on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>