Issues using --pipe

[Jay Hacker]

I'm not sure if this is my own misunderstanding of --pipe or bugs, but
maybe somebody can help me.  I'm using version 20111122 on CentOS 5.6
x86-64.

First, if I forget the job, I get a weird message and parallel hangs:

$ seq -w 10 | parallel --pipe
Deep recursion on subroutine "CommandLineQueue::get" at
/usr/bin/parallel line 4190.

Second, it seems to be launching jobs for input blocks that don't
exist; the number of times the 'EOF' marker gets printed below changes
from run to run:

$ echo EOF > marker.txt
$ seq -w 10 | parallel --pipe --block-size 3 cat - marker.txt
01
EOF
02
EOF
03
EOF
04
EOF
05
EOF
06
EOF
07
EOF
08
EOF
09
EOF
EOF
10
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF
EOF


This is a 16-processor machine; the same thing happens if I explicitly
specify -j16, or any number of jobs greater than 2.  I would expect it
not to launch jobs for input blocks that don't exist, and a variable
number of jobs seems strange in any case.