Some Endless OS versions were unfortunately released with a bug where it is not possible to perform an OS upgrade through the App Center. In this case, the App Center does not mention the availability of any OS update, even though newer versions are available.
This is not a normal situation, only the following Endless OS releases are affected by this issue:
To check which release you are running:
If you believe you are affected by this issue, and have confirmed that you are running one of the affected releases listed above, follow these steps:
Open the Terminal app
Type or copy-paste following command then press enter key to run the command:
sudo ostree admin upgrade
You may be prompted for your user account password. Your password may not appear as you type it in, but if prompted, type it in anyway and press Enter.
This command may take quite some time to complete, as it downloads and installs an updated version of Endless OS.
Reboot the system
You will now be in a newer version of Endless OS, and you can obtain further updates via the App Center as normal.
The following supplemental information is intended for developers and technicians.
Unfortunately the eos-updater component in these affected releases has a memory corruption bug which results in the following types of failure:
eos-updater[1491]: libostree pull from 'eos' for os/eos/nexthw/eos3.4 complete
eos-updater[1491]: Using product branch os/eos/nexthw/eos3.4
eos-updater[1491]: libostree pull from 'eos' for os/eos/nexthw/eos3.4 complete
eos-updater[1491]: Failed to poll metadata from source main: Invalid refspec 0$p;
eos-updater[1491]: Changing to state Ready
The "Invalid refspec" is random memory (changes every time). At this point the UI doesn't hint that any update is available. This bug was fixed with edba7da69f or 3c08bc9cde.
Immediately preceeding and following releases (EOS-3.4.3 and EOS-3.4.4-nexthw1) have been tested and confirmed that they are not affected by this issue.