[Help-bash] Using lastpipe causes function that takes stdin to fail

[Jesse Hathaway]

I ran into a strange issue last week when attempting to pipe some
output into a bash function. The function would always return with an
error code of 127. I was able to narrow the cause down my use of the
`lastpipe` option. When I run the below minimal test case without
`lastpipe`, it completes successfully, but when I use `lastpipe`, the
function returns an error code of 127. I ran the failing program
through strace and it appeared the problem might be due to a wait
system call that doesn't find any matching pids? Any help would be
greatly appreciated, i'm stumped.

; cat lastpipe
#!/bin/bash

set -o pipefail

function bubbles() {
        cat | cat
        date
}

if echo 'butter' | bubbles; then
        echo "SUCCESS: $?"
else
        echo "FAILED: $?"
fi

; bash lastpipe
butter
Mon Nov 12 09:10:13 CST 2018
SUCCESS: 0

; bash -O lastpipe lastpipe
butter
Mon Nov 12 09:10:20 CST 2018
FAILED: 127