cannot create user data directory: /home/mg/snap/ripgrep/8: Not a directory

[Marius Gedminas]

A while ago I installed ripgrep on a server with

    sudo apt install snapd
    sudo snap install ripgrep --classic
    sudo snap alias ripgrep.rg rg

and it didn't work for me:

    $ rg --help
    cannot create user data directory: /home/mg/snap/ripgrep/4: Too many levels of symbolic links

but I was busy and didn't file a bug. Today it still doesn't work, but the error message is different:

    $ rg --help
    cannot create user data directory: /home/mg/snap/ripgrep/8: Not a directory

Possibly relevant information (especially given the symlink reference in the original error message): my home directory according to /etc/passwd is /home/mg, which is actually a symlink to ../home-ssd/mg. /home is an ext4 partition on a MD RAID-1 device on spinning rust, /home-ssd is an ext4 partition on an LVM volume (mirrored as raid-1) on a pair of SSDs. /home-ssd is too small to contain all the home directories, hence the selective symlinking.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: snap (not installed)
ProcVersionSignature: Ubuntu 4.15.0-91.92-generic 4.15.18
Uname: Linux 4.15.0-91-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.11
Architecture: amd64
Date: Wed Mar 18 14:42:48 2020
SourcePackage: snap
UpgradeStatus: Upgraded to bionic on 2019-09-11 (188 days ago)

[Zygmunt Krynicki (zyga)]

This kind of home setup is not supported by snapd.

You can work around it by actually _mounting_ your home, form whichever filesystem or raid configuration at /home/$LOGNAME. You can also use a bind mount for the same effect.

[Zygmunt Krynicki (zyga)]

I'm marking this as invalid. Eventually we would like to support magically transitioning whichever home directory the user has on the system to appear as /home/$LOGNAME for snaps but this is hard for many reasons.

[Marius Gedminas (mgedmin)]

Just to clarify, does this mean root can't use snaps too, or is /root handled specially?

[Zygmunt Krynicki (zyga)]

I'm sorry for being unclear, /root and /home/* are both okay though neither item can be a symbolic link.

As I said eventually we will be able to map /whatever to /var/home/$LOGNAME, most likely, but it requires some PAM integration to get right.