gnuradio crashes with CtrlPort Performance Monitor Enabled

[wasutton3]

GnuRadio crashes with the error message while using the following .grc file https://paste.ubuntu.com/p/XMJgk462px/

`ControlPort Monitor running.
python3: ../gnuradio-runtime/lib/controlport/rpcmanager.cc:38: static rpcserver_booter_base* rpcmanager::get(): Assertion `booter_registered || aggregator_registered' failed.`

Steps to reproduce:

1) Install gnuradio
2) Download this file as file.grc
3) Open file.grc with gnuradio-companion
4) Execute flowgraph.
5) Observe bug.

The issue seems to be reported here as well. https://github.com/gnuradio/gnuradio/issues/3673
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27.10
Architecture: amd64
CasperMD5CheckResult: skip
DistroRelease: Linux Mint 20
InstallationDate: Installed on 2019-12-31 (301 days ago)
InstallationMedia: Linux Mint 19.3 "Tricia" - Release amd64 20191213
Package: gnuradio 3.8.1.0~rc1-2build2 [origin: Ubuntu]
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.3.0-24.26~18.04.2-generic 5.3.10
Tags: ulyana third-party-packages
Uname: Linux 5.3.0-24-generic x86_64
UnreportableReason: This is not an official Linux package. Please remove any third party package and try again.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dialout dip libvirt lpadmin plugdev sambashare sudo
_MarkForUpload: True
mtime.conffile..etc.gnuradio.conf.d.grc.conf: 2020-02-19T10:27:42.529223

[wasutton3 (will-sutton-family)]

apport information

[wasutton3 (will-sutton-family)]

apport information

[wasutton3 (will-sutton-family)]

apport information

[wasutton3 (will-sutton-family)]

apport information

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[lotuspsychje (lotuspsychje)]

Ubuntu 20.04.1 all up to date to latest @ 27/10/2020 with kernel 5.4.0-52-generic

the steps above are reproducible to get the python error;

python3: ../gnuradio-runtime/lib/controlport/rpcmanager.cc:38: static rpcserver_booter_base* rpcmanager::get(): Controletest 'booter_registered || aggregator_registered' faalt.

[wasutton3 (will-sutton-family)]

There appears to be a set of patches coming down the pipe that will resolve this issue.

Please see this PR for details:

https://github.com/gnuradio/gnuradio/pull/2739