I am trying to run the latest appimage for gSender on my Ubuntu laptop. The file is marked as executable but when I try to run it, nothing happens.
I could have sworn that I had this running some time ago but I am stumped - what am I missing?
(note: no cnc machine is connected)
gSender-1.4.9-Linux-Intel-64Bit.AppImage
After a lot of farting around, I seem to have a solution. Something changed in Ubuntu 24.04 and I can no longer just click on the appimage file and select ‘run as a program’. Apparently there is something that needs to be changed when the Appimage file is created. There are other appimage files that do not run and there are appimage files that do run.
To get gSender to run, it has to be done via the command line with the option ‘–no-sandbox’.
What I have discovered is a workaround. The real fix would be if whoever maintains the appimage package would do whatever needs to be done to fix the incompatibility with Ubuntu 24.04.
Apparently 24.04 breaks many things and I will be looking into downgrading to an earlier release.
If you haven’t done this try it. Right click on file. click on properties. click on permissions, go down to execute and check box, (Allow executing file as program). Close out and left click on file it should now open program.
As per my original post, the file was marked as executable. It was the first thing I did.
Thanks for your reply.
Ubuntu deprecated unprivileged kernel namespaces by default as of 24.04. There is not a workaround for this on the software side.
You can read more about the change on the Ubuntu release in the security section:
It’s more likely we’ll update the documentation on how to add a AppArmor profile to Ubuntu or disable it completely (easy but please don’t do this). I know some distros (Mint, specifically) already rolled back this change.
Thanks, I will read up on this but I question your assertion that there is no work-around for this. The reason I am saying this is Prusa Slicer. It comes as an AppImage and works just fine in Ubuntu 24.04. I should note that the current version of Prusa Slicer, which was released rather recently, has two versions with the second version specifically compiled for Ubuntu 24.04. It runs just fine! The version for non Ubuntu 24.04 fails the same way as gSender does. To me this says that ‘clearly there is a software answer’ to this issue.
Just had a look at the release notes you mentioned. They offer several fixes including a suggesting re AppArmor profiles. Unfortunately this is well above my pay grade. They also speak about a new release (24.04.1) that is expected to be released on Aug 15 … maybe that will include a fix of some sort.
Anyway, as you said, documentation on how to add an AppArmor profile would be great and should do the job.
I followed the instructions in the Ubuntu release notes and everything works now (at the risk of higher security vulnerability)!
Specifically:
Disable this restriction using a persistent setting by adding a new file (/etc/sysctl.d/60-apparmor-namespace.conf) with the following contents:
kernel.apparmor_restrict_unprivileged_userns=0
Reboot. This is similar to the previous behaviour, but it does not mitigate against kernel exploits that abuse the unprivileged user namespaces feature.
You can question what you like, but it’s not the fact that it’s an AppImage, it’s the fact that Electron/Chromium requires namespaces. You don’t see it in PrusaSlicer because it’s not an Electron application.
This effects us because we are using Electron - and that’s the consistent factor across the majority of the other affected apps (VSCode is the big one, but any issue will show a number of other impacted applications).
It’s not fixable on our end unless A) Electron changes or b) you fix it on your operating system.
Interesting … in any case, I have chosen option B and everything is working now.
@Jens Since everything is working now, I’ll close the topic.