i do not believe this is correct. it reverts 8721eb0 (without indicating so in the commit log, nor why. /etc is deprecated for that stuff: debian packages warn loudly about it. specifically, the error I got was:

W: pass-extension-update: package-installs-into-obsolete-dir : ^etc/bash_completion.d/ -> usr/share/bash-completion/completions Ensure new filename matches stricter requirements (see https://bugs.debian.org/776954 and https://bugs.debian.org/814599) [etc/bash_completion.d/pass-update]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=776954 has the detailed rationale, and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=814599 has more info about naming conventions.

Thanks, I can see now this is just a temporary workaround (until /etc/bash_completion.d is removed) not a solution.
I close this PR.