Strange testsuite behavior on AMD64, more info

[Scott Robert Ladd]

In a nutshell: The GCC testsuite is reporting spurious failures on 
systems running gentoo-amd64 (a pure 64-bit Linux distro). A "make -k 
check" results in thousands of reported "failures." After quite a bit of 
testing and research with folk on the gentoo-amd64 IRC, the problem is 
narrowed down to...

If I go into build/gcc/testsuite, and run:

   scott@Corwin testsuite $ runtest --tool gcc -v

I see a thousands of failures reported like this one:

   Testing gcc.c-torture/execute/builtins/abs-1.c,  -O0
   doing compile
   pid is 8273 -8273
   output is
   spawning command /home/scott/projects/gnu/build/gcc/testsuite/abs-1.x0
   spawn -open file6 failed, 1 fdopen: bad file number, fdopen: bad file 
   number
       while executing
   "spawn -leaveopen file6"
   FAIL: gcc.c-torture/execute/builtins/abs-1.c execution,  -O0

I've been at this for a couple of hours, as have other gentoo-amd64 folk 
who have the same problem. This appears to be some sort of problem with 
the testing harness, perhaps an incompataibility of some sort.

I'm hoping someone here has an "Aha!" moment accompanied by an obvious 
solution.

-- 
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
Software Invention for High-Performance Computing