The 'source x' command doesn't keep variables set by x when source output is piped into other command

[Yuri]

This script:

#!/usr/bin/env bash
# write child script
echo "export XVAR=xx" > child.sh
echo "YVAR=yy" >> child.sh

# source is piped into tee
source child.sh | tee /dev/null
echo "XVAR=$XVAR"
echo "YVAR=$YVAR"

# source is un-piped
source child.sh
echo "XVAR=$XVAR"
echo "YVAR=$YVAR"



prints this:

XVAR=
YVAR=
XVAR=xx
YVAR=yy


The first 'source' command didn't set variables set or exported in the 
child.sh script, even though 'source' is executed in the current 
script's context, and it should behave as if these commands were 
executed in-place.

Piping source's output into another command shouldn't change its 
variables-related behavior.


bash-5.2.32



Thanks,

Yuri