Hi Callum,
the process you are seeing running is not "srspec", but the helper script "osmo-gsm-tester_setcap_net_admin.sh" run with sudo in order to set the required capabilitites to the "srsepc" binary before actually running it.
So to me it looks like the job is stalled running "sudo" which will probably be asking for a password.
I bet if you check the output log of "setcap-netadm" process under the osmo-gsm-tester output directory you will find sudo asking for a password printed there.
You probably need to configure sudo on that machine to avoid requesting a password for that specific script (yes, it may pose a security risk).
See osmo-gsm-tester.git "utils/bin/osmo-gsm-tester_setcap_*" and "utils/sudoers.d/osmo-gsm-tester_setcap_*", and check osmo-gsm-tester manual for further info.
regards, Pau