Warning and Disclaimer are blank, continuing results in Failed Restore

[sgornick]

Describe the bug
After the Parsing log file, the dialog then shows what should be a Warning and Disclaimer, however I only see those titles, no content. Hitting Next appears to continue, but the Restore will result in the message saying it failed. From my troubleshooting, it appears this occurs when the margin of disk space available beyond what is needed for the snapshot is not large. (e.g., Snapshot is for a 15GB partition which had 13GB of space used).

To Reproduce

1. Create a snapshot for a computer where the operating system is on a partition that is nearly full (e.g., 13GB of 15GB used). The snapshot destination is the partition that has /home.
2. Reboot into Ubuntu 20.04.1 LTS LiveUSB
3. Format the partition that the snapshot is for.
4. Launch Timeshift, Attempt to Restore snapshot.
5. After Parsing the log file, presented are Warning and Disclaimer, however they are blank -- no content. This snapshot restore will be reported by Timeshift as having failed.

Expected behavior
Warning and Disclaimer showing at least the partition(s) that the snapshot Restore will write to. After clicking Next, the snapshot restore should complete successfully. Even though the partition was the same size as it was when the snapshot was created, restore of that snapshot will fail. By re-creating the partition with a larger size (e.g., 20GB), the next attempt to restore did show expected results in the Warning and Disclaimer, and the restore was successful.

System:

• Ubuntu 20.04.1 LTS Desktop
• Timeshift v20.03
• The snapshot restore attempt was done while running Ubuntu 20.04.1 LTS LiveUSB

Additional Information:
This seemed bizarre but I had done this numerous times and could replicate this behavior. Some of the files being restored were Snaps that were very large (e.g., 300MB). I had even tried installing a clean Ubuntu 20.04.1 LTS O/S and restore running that instead of the LiveUSB. The screen message on that showed the restore attempt had ended when it had run out of disk space copying a snap (vlc_1700.snap, 305MB).

[dandv]

I also ran into this issue, after trying to restore a failed update - linuxmint/cinnamon#9922

After continuing with the restore, it completely borked my system. After rebooting I kept seeing the Mint logo spinning for 10+ minutes:

When pressing some key combo, I saw this screen:

Then everything was broken so I had to reinstall, but I lost confidence in Mint and switched to Kubuntu.

[LinuxOnTheDesktop]

The problem reported here, by more that one user, seems rather serious. Yet, and even though Timeshift is bundled with Linux Mint, the bug report has received no developer attention. Compare also the fact that even when restores succeed the 'warning' and 'disclaimer' fields can remain blank for a disconcertingly long time. (On that latter problem, see here. I myself have encountered that problem.)