# here the die runs in the child:
nph>perl -MIPC::Open3 -le'print "dad: $$";eval {$pid = open3(*IN, *OUT, *ERR, @ARGV);}; die "$$ ACK $@\n" if ($@);print <ERR>' nosuch
dad: 62718
55596 ACK open3: exec of nosuch failed at -e line 1

# yet here in the same code it runs in the parent !!!
nph>perl -MIPC::Open3 -le'print "dad: $$";eval {$pid = open3(*IN, *OUT, *ERR, @ARGV);}; die "$$ ACK $@\n" if ($@);print <ERR>'
dad: 25600
25600 ACK open3(*main::IN, *main::OUT, *main::ERR): not enough arguments at -e line 1

# and if I remove the print <ERR> I alter the behaviour again
nph>perl -MIPC::Open3 -le'print "dad: $$";eval {$pid = open3(*IN, *OUT, *ERR, @ARGV);}; die "$$ ACK $@\n" if ($@);print "moo" ' nosuch
dad: 55592
moo
nph>