Virtualenv: activate.fish uses unsupported 'source' command

The fish shell website tells differently.

https://fishshell.com/docs/current/commands.html#source

. (a single period) is an alias for the source command. The use of . is deprecated in favour of source, and . will be removed in a future version of fish.

Who am I to believe?

Sorry, I rushed to a conclusion after reading issue #211 on the fish shell page.

Apparently the same concern was raised in issue #310 and was addressed in the latest version of fish

The issue on my system was because apt-get only installs fish 2.0.0 by default and a separate repository needs to be added in order to get the version (2.2.0) in which the source command was introduced. Adding the PPA repository fish-shell/release-2 and upgrading the fish package fixed the issue. Thanks so much for your help and sorry about the confusion.

Really? I am no fish version 2.3.1 and source of a virtualenv activate file does not work.

source ~/.venvs/base/bin/activate
Unsupported use of '||'. In fish, please use 'COMMAND; or COMMAND'.
~/.venvs/base/bin/activate (line 23):     if [ -n "${BASH-}" ] || [ -n "${ZSH_VERSION-}" ] ; then
                                                                ^
from sourcing file ~/.venvs/base/bin/activate
    called on standard input

source: Error while reading file '/Users/satkins/.venvs/base/bin/activate'

@sjatkins you are sourcing the activate script, designed for bash / zsh / etc, instead of activate.fish