Re: [Libguestfs] [libnbd PATCH v4 0/2] lib/utils: introduce async-signal-safe execvpe()

The solution is that glibc *too* has a bug, and that bug hides the busybox bug. Namely, in glibc, going back to historical commit commit 6a032d81581978187f562e5533a32e0a6a3d352b (tag: cvs/libc-960210) Author: Roland McGrath <roland(a)gnu.org&gt; Date: Sat Feb 10 10:00:27 1996 +0000 Sat Feb 10 04:18:48 1996 Roland McGrath <roland(a)churchy.gnu.ai.mit.edu&gt; * posix/execvp.c: If execv fails with ENOEXEC, run the shell on the file. Fri Feb 9 11:46:45 1996 Roland McGrath <roland(a)churchy.gnu.ai.mit.edu&gt; * time/Makefile (CFLAGS-zdump.c, CFLAGS-zic.c, CFLAGS-ialloc.c, CFLAGS-scheck.c): Use -DNOID instead of -Wno-unused. * hurd/Makefile (user-interfaces): Added hurd/tioctl. (note the date: 1996!), the POSIX-mandated fallback execv(<shell path>, { argv[0], file, argv[1], ..., NULL }) is not being done. Instead, the following is done: execv(<shell path>, { <shell path>, file, argv[1], ..., NULL }) In other words, the original argv[0] is not preserved, but is replaced by <shell path>. (Look for _PATH_BSHELL in said historical glibc commit, and also in today's glibc file "posix/execvpe.c".)