Delays lines written to a source file before appending them to a destination file.
delay-pipe <source> <dest> <delay_secs>
touch /tmp/src
delay-pipe /tmp/src /tmp/dst 5 &
echo "hello" >> /tmp/src
sleep 5
cat /tmp/dstcargo build --releasecargo test
cargo test stress -- --ignored --nocapture # 100k lines/sec for 60s