Comment 1 for bug 676987

commit 6cfdd9e66519b513e0935c410fbb30fc880efb61
Author: Nicolas Edel <email address hidden>
Date: Fri Nov 18 12:49:22 2011 +0200

    pass errno from exec() to parent in spawn()

      Open a pipe, set FD_CLOEXEC.

      Child: if exec() fails, grab errno and write it to pipe.

      Parent: try to read from the pipe -- if you get something, it means the
      child didn't exec and the reason is in the pipe. Wait for the child to exit
      and return -1 and set errno to whatever the child got.

      Also use _exit() instead of exit() when dying in the child after exec
      failure -- running exit hooks there would probably be bad.

      (Somewhat edited from Nicolas' original patch.)

    Signed-off-by: Nikodemus Siivola <email address hidden>