Thanks for this problem report and sorry for the trouble. We think this will be fixed once https://github.com/snapcore/snapd/pull/6473 lands (which should happen today).
The fix for this is now in the “core” snap in the beta channel. Once it passed our QA it will be released to the candidate channel (and eventually stable).
I cannot launch notepad-plus-plus… getting
cannot perform operation: mount --rbind /var/tmp /tmp/snap.rootfs_8bmcBE//var/tmp: Permission denied
I thought this was from the following security hardening I had done…
Let’s create a 1GB (or what is best for you) filesystem file for the /tmp parition.
sudo fallocate -l 1G /tmpdisk
sudo mkfs.ext4 /tmpdisk
sudo chmod 0600 /tmpdisk
Mount the new /tmp partition and set the right permissions.
sudo mount -o loop,noexec,nosuid,rw /tmpdisk /tmp
sudo chmod 1777 /tmp
Set the /tmp in the fstab.
sudo nano /etc/fstab
: /tmpdisk /tmp ext4 loop,nosuid,noexec,rw 0 0
sudo mount -o remount /tmp
sudo mv /var/tmp /var/tmpold
sudo ln -s /tmp /var/tmp
sudo cp -prf /var/tmpold/* /tmp/
sudo rm -rf /var/tmpold/
Can’t say this is the reason however, I see a lot of people are running into the same issue so I’ll keep an open mind. I ran snap refresh --candidate core and installed notepad-plus-plus from there and still get the same error message when trying to load. This time
cannot perform operation: mount --rbind /var/tmp /tmp/snap.rootfs_gtO0J2//var/tmp: Permission denied
Updated; tested on a separate ubuntu vm, everything installed fine; but after securing temp folders according to the template above it breaks snap installations the same.