zsh - PATH set before /etc/zshenv

I am trying to find which file adds /opt/texbin folder to my PATH variable on Ubuntu. It is not present in my /etc/environment file. sudo grep -lr texbin . 2>/dev/null outputs nothing in the /etc folder. And still if I add set -x to the beginning of my /etc/zshenv file I can see that /opt/texbin is in my PATH before zsh sources this file.

Any ideas?

Answer

I would try this approach to track down the source of /opt/texbin in your PATH variable:

1. 
   

   To get a list of files, which are actually read in (e.g. a non-standard file might be sourced by another file!), you can invoke zsh with the SOURCE_TRACE option enabled:

   
   

   $ zsh -o sourcetrace
   +/etc/zshenv:1> 
   +/home/user/.zshrc:1> 
   +/home/user/.zcompdump:1> 
   +/home/user/.zshrc-last:1> 
   



2. 
   

   Check these files, where the PATH variable come into play:

   
   

   $ grep -ie "path.*=" files_from_step_1
   

   
   

   The case insensitivity is crucial, since zsh uses the array $path, which automatically gets converted to the bash-like colon-separated list $PATH and vice versa.

   
   


3. 
   

   If still not lucky, try to include a debug message in /etc/zshenv, where commands are first read from:

   
   

   print -l $path
   

   
   

   This will give you a nice list of the PATH variable, which zsh inherits from its parent process (display manager, init process, etc.).^*

   
   


4. 
   

   If the path is indeed inherited from the starting process, it is crucial to know which processes are relevant:

   
   

   $ pstree -apH $$
   

   
   

   This produces a process tree, where the shell process (pid in $$) is highlighted. Check the config files for these processes, too, and keep in mind that

   
   
   
   
   • source /some/file or . /some file can also alter the PATH
   
   
   • if you edit e.g. /etc/profile in your current console, log off and log in again, the parent process (X logon manager) might still have the old environment.⁺
   
   
   
   

---

^* As you have written, the PATH already contains /opt/texbin before /etc/zshenv is read, checked by set -x in /etc/zshenv. I get no output with this technique, but with my step 3, hence I included the other steps in my answer as well.

⁺Suffered myself badly due to this behavior some time ago...