LXDE 2.8b7 Change Hostname Issues

I need my application users to be able to change the machine’s network hostname, preferably without having to reboot.
I happen to be using the 2.8b7 Yokto build with Qt5.9.9 built in to it, which I baked myself. There’s a few things I altered in the build, but it’s based on the standard Angstrom image.
Typically, I’d use the *hostname * command, edit the /etc/hostname file and edit the /etc/hosts file. This is the sort of thing I’d do in any Linux distribution. Or maybe I’d use the *hostnamectl set-hostname * command instead, since it updates the /etc/hostname file for me.
It doesn’t work. The moment I either edit the /etc/hosts file or issue the hostname or hostnamectl commands, I lose the ability to use any of the apps in the menu (i.e.: PCManFM, for example) - they stop working. My application suffers a segfault when my code tries to change the hostname, too.
This wasn’t an issue in build 2.6. What am I missing?
Any help gratefully appreciated - thank you!

#Change the hostname
hostnamectl set-hostname "$newname"
#Update /etc/hosts
sed -i "s/$oldname/$newname/g" /etc/hosts  #Or do it manually with LeafPad
#At this point, try clicking on the menu and opening a built-in app, such as Florence or PCManFM - it won't open.
#My segfaulting Qt app reports "no protocol" or something like that

Hello @Fractal ,

Thank you for your message, Please be kindly noted that the Angstrom image from Toradex has been deprecated already a while ago and is not supported anymore. We recommend our customers to upgrade to our latest BSP (eg., BSP 5.0+), when possible.

But you might find your answers in the following developer article and the link:

https://developer.toradex.com/knowledge-base/ethernet-network-linux

https://pythonhosted.org/pyconnman/config.html

Best Regards,
Janani

Thanks for replying. I reverted back to Angstrom because I need to deploy VNC and it was the easiest route for me, it being X11 so I could build “x11vnc” in to Yocto by default, really simply. I’ll try the links you suggested, thanks. When I have time I’ll look at the new BSP’s too, but we can’t keep upgrading all the time because we very quickly lose track of our in-the-wild-already-deployed devices. Stability is really important to us.