We're using fake root environment at work. Basically it is a bunch of directories which emulate apt-get and dpkg if some environment variables are set. I.e. you run apt-get install xxx and package xxx is being installed into this environment but not into the system.

When I used bash, apt-get autocomplete worked perfectly. When I typed apt-get install <Tab><Tab>, it showed me the list of local packages if I was in a fake root and the global list otherwise.

However, when I switched to zsh weird things happened. Currently only global packages show up in the list, though it was not always the case. Here is the complete story.

  1. I install Ubuntu and setup the fake root and zsh.
  2. I reinstall Ubuntu from scratch, saving /home which was on a separate partition.
  3. Now zsh autocomplete always show me the packages from the fake root, regardless whether I have the env vars set.
  4. I reinstall zsh and zsh-common. Now completion always work as no fake root exist. At the same moment I realize that after reinstall the folder Ubuntu disappeared from /usr/share/zsh/functions/Completion, now apt-get completion rules are taken from Debian folder.

Could you please explain me what could happen here and how can I setup zsh completion work with both system and fake apt-get?

I use Ubuntu 16.04.2.

P.S. My fake root is not related to fakeroot command.

1 Answer 1


Well, I have finally figured it out. Zsh completion engine caches several things, including the list of available packages returned by apt. Now my story seems clear: when autocomplete always suggested me packages from the fake root it was because first time I ran zsh in the fake root environment and the corresponding package list got into a cache.

If you want to override it (assuming you use oh-my-zsh) just add the following code into your .zshrc before calling oh-my-zsh:

if [[ check for fakeroot ]]; then
  export ZSH_CACHE_DIR=desired-cache-dir-name

This separates completion caching between fake root and the base system and solves the problem from the post.

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