Using `su` can cause `$XDG_*` vars to get set to subfolders of `/root`, which messes up Znap initialization

[pedromarquetti]

Describe the bug

I just started using znap, followed the basic dotfiles usage for my (phlm) and root users, but when I $ sudo su then # su phlm, some "zf_mkdir" errors appear, followed by an infinite autocomplete loop

Steps To Reproduce

sudo su
su <your user>

Expected behavior

Normal switch between root user and my user with sudo su and su <my user>

Observed behavior

Currently, when I su <my user> after doing sudo su, apparently my shell is trying to mkdir /root/.local (even though I just switched to my non-root user with su), see log below

Click to expand

phlm% whoami
phlm
phlm% sudo su
[sudo] password for phlm: 
phlm# whoami
root
phlm# su phlm
init.zsh:zf_mkdir:44: cannot make directory '/root/.local': permission denied
init.zsh:zf_mkdir:44: cannot make directory '/root/.cache': permission denied
init.zsh:zf_mkdir:44: cannot make directory '/root/.cache': permission denied
init.zsh:zf_mkdir:44: cannot make directory '/root/.config': permission denied
init.zsh:zf_mkdir:44: cannot make directory '/root/.local': permission denied
init.zsh:zf_ln:61: /home/phlm/Git/zsh-snap/functions/_znap: permission denied
.autocomplete.__init__:zf_mkdir:81: cannot make directory '/root/.local': permission denied
.autocomplete.__init__:zf_mkdir:85: cannot make directory '/root/.local': permission denied
.autocomplete.__init__:zf_mkdir:103: cannot make directory '/root/.cache': permission denied
.autocomplete.async.start:6: permission denied: /root/.local/share/zsh-autocomplete/log/2022-07-01.async.log
.autocomplete.async.complete.fd-widget:3: permission denied: /root/.local/share/zsh-autocomplete/log/2022-07-01.log
... infinite loop ...

Environment:

• OS: Pop!_OS 22.04 LTS x86_64
• Terminal: Tilix
• Zsh version: zsh 5.8.1 (x86_64-ubuntu-linux-gnu)
• Repo version: main de2e7c6

Additional context

I used Oh My Zsh previously and it was working fine with only zsh-autocomplete, zsh-autosuggestions and zsh-syntax-highlighting, I wanted to change to zsnap for being light-weight. I'll include my zshrc, but I changed it multiple times, still the same result...

My .zshrc

# Download Znap, if it's not there yet.
[[ -f ~/Git/zsh-snap/znap.zsh ]] ||
    git clone --depth 1 -- \
        https://github.com/marlonrichert/zsh-snap.git ~/Git/zsh-snap
source ~/Git/zsh-snap/znap.zsh  # Start Znap
znap source automatically downloads and starts your plugins.
znap source marlonrichert/zsh-autocomplete
znap source zsh-users/zsh-autosuggestions
znap source zsh-users/zsh-syntax-highlighting

Am I doing something wrong?

[marlonrichert]

Looks like, when you do su <user> either

• $HOME is set to /root or
• $XDG_CACHE_HOME, $XDG_CONFIG_HOME and $XDG_DATA_HOME are set to /root/<subdir>

and when using su <user>, /root is not writable and /home/<user>/Git/zsh-snap is not readable.

[marlonrichert]

Can you try doing su -m user? Does that solve the problem?

[pedromarquetti]

Can you try doing su -m user? Does that solve the problem?

It does solve the problem, it doesn't try to write to /root/, but then znap + auto-complete and auto-suggestions is not loaded.

[marlonrichert]

Does it give any error messages?

[pedromarquetti]

No. It only shows the default phlm% prompt. Do you think it's some misconfiguration? I could also send some log files (the ones that were able to be written)

Also, just to add, if I comment out znap source marlonrichert/zsh-autocomplete from .zshrc, the infinite loop doesn't happen, but it still gives the permission denied error that I mentioned

[marlonrichert]

Before doing su, can you put set -vx in your .zshrc file (before sourcing Zsh Autocomplete) and share the output here in a file?

[pedromarquetti]

Ok, so I don't understand why set -xv >/tmp/zsh.log is not working when doing sudo su > su phlm , I had to manually copy my terminal.

The log i got after doing su with zsh-autocomplete, there's an long loop there, i had to su phlm to stop it. zsh-autocomplete.log

The log I got after I ran su without zsh-autocomplete sourced: zshrc.log

Hope this helps

[marlonrichert]

Your zsh-autocomplete.log is 0 KB. Did your upload fail somehow?

[marlonrichert]

What happens if, instead of using znap source to start Zsh Autocomplete, you use just source?

[pedromarquetti]

Your zsh-autocomplete.log is 0 KB. Did your upload fail somehow?

Now it uploaded correctly zsh-autocomplete.log, I did su phlm at the end to stop the loop.

What happens if, instead of using znap source to start Zsh Autocomplete, you use just source?

If I do source ~/Git/zsh-autocomplete/zsh-autocomplete.plugin.zsh, same loop occurs

[marlonrichert]

Can you comment out most of the things in your .zshrc and leave only the minimum that’s necessary to reproduce the bug? Then share your debug output here again.

[pedromarquetti]

I commented out everything and did the test 4 times:

no-autocomplete with set -vx after sourcing znap.zsh no-autocomplete and set -vx before sourcing znap.zsh with autocomplete enabled, with set -vx after sourcing znap.zsh autocomplete enabled and set -vx before sourcing znap.zsh

[pedromarquetti]

What is "XDG_CACHE_HOME", "XDG_CONFIG_HOME" and "XDG_DATA_HOME" used for? I added

export XDG_CACHE_HOME=$HOME/.cache
export XDG_CONFIG_HOME=$HOME/.config
export XDG_DATA_HOME=~/.local/share

At the beginning of my .zshrc and no errors or infinite loops occur

[marlonrichert]

OK, thanks. That’s a good clue.

In your .zshrc, before setting or exporting those, can you add

print -lr "${(q+)HOME}" "${(q+)XDG_CACHE_HOME}" "${(q+)XDG_CONFIG_HOME}" "${(q+)XDG_DATA_HOME}"

and share the output here?

[pedromarquetti]

/home/phlm
''
''
''
~ $ sudo su                                                                         
[sudo] password for phlm: 
~ # su phlm                                                                
/home/phlm
/root/.cache
/root/.config
/root/.local/share                                                                            

[marlonrichert]

OK, so, for some reason, when you expand your user's privileges with su, then $XDG_CACHE_HOME, $XDG_CONFIG_HOME and $XDG_DATA_HOME get set. You need to disable this somehow.

Can you check the following files and see if they get set somewhere in there?

/etc/zshenv
/etc/zprofile
/etc/zshrc
/etc/zlogin
/etc/zlogout

[pedromarquetti]

Zsh has its own zsh folder inside /etc/, with

-rw-r--r-- 1 root root  344 Feb 12  2022 zlogin
-rw-r--r-- 1 root root   58 Feb 12  2022 zlogout
-rw-r--r-- 1 root root  264 Feb 12  2022 zprofile
-rw-r--r-- 1 root root  623 Feb 12  2022 zshenv
-rw-r--r-- 1 root root 3900 Feb 12  2022 zshrc

all of the files insite /etc/zsh are unchanged, and XDG variables do not get set in any of them

[marlonrichert]

What needs to be done is

1. For each XDG dir, check if it is writable for us.
2. If not, set it to the default value instead.
3. If the default value is not writable to us either, then bail out and show an informative error.

Pull requests welcome. 🙂