OK, this error message is benign and will be fixed in the next IO::Pty version (coming up soon).
The hangup is related to a missing close-on-exec flag on a pipe filehandle in Expect and will also be fixed like this:
*** Expect-1.15/Expect.pm Tue Mar 19 12:59:29 2002
--- Expect-1.16/Expect.pm Fri May 5 13:30:06 2006
***************
*** 104,109 ****
--- 104,112 ----
# set up pipe to detect childs exec error
pipe(STAT_RDR, STAT_WTR) or die "Cannot open pipe: $!";
STAT_WTR->autoflush(1);
+ eval {
+ fcntl(STAT_WTR, F_SETFD, FD_CLOEXEC);
+ };
my $pid = fork;
