[Pkg-zsh-devel] Bug#970848: Bug#970848: Problem with path to completion scripts

[Daniel Shahaf]

Frank Terbeck wrote on Fri, 25 Sep 2020 00:02 +0200:
> Georgy Komarov wrote:
> > I encountered with a problem, when trying to use custom zsh completions.  
> 
> As debian/README.Debian states:
> 
> Load-path for functions from other packages
> -------------------------------------------
> 
> In respsonse to #620452, the zsh-binary from Debian's zsh package started to
> provide two entries to $fpath (the search path for loadable functions) for
> other packages to drop function files into:
> 
>   - /usr/share/zsh/vendor-completions for functions that add functionality to
>     zsh's function based completion system (compsys)
> 
>   - /usr/share/zsh/vendor-functions for all other functions
> 
> If you maintain another Debian package that wants to add functions to zsh's
> function load-path, please use the those conventions when installing function
> files.

These directories are added to $fpath near the start.  Therefore, files
dropped into them will override files provided further down $fpath,
which in particular includes completion functions shipped with zsh
upstream.  In particular, if [a file dropped into] vendor-completions
and zsh upstream both provide completion for /usr/bin/foo, then the
former will be used — even though it's not necessarily the better of
the two.

Recommend to review collisions on a case-by-case basis and resolve
duplications (between zsh on the one hand, and zsh-completions or other
upstreams on the other hand) as needed.

Note that to look for collisions, it's not sufficient to look for
filename collisions, since for a given external command (say,
systemctl(8)) zsh upstream and a third-party upstream might use
different filenames and function names (e.g., "_systemd" v.
"_systemctl").

Cheers,

Daniel