[rc] flag e + causes double fork(), which renders $apid unreliable

[dexen]

test script:

#!/usr/bin/env rc

flag e -
echo flag e - works as expected:
rc -c 'echo inner pid: $pid' &
echo outer pid: $apid
wait

flag e +
echo flag e + bugs out:
rc -c 'echo inner pid with e +: $pid' &
echo outer pid with e +: $apid
wait

output:

flag e - works as expected: outer pid: 20923 inner pid: 20923 flag e + bugs out: outer pid with e +: 20927 inner pid with e +: 20929