glibc/linuxthreads/configure.in

GLIBC_PROVIDES dnl See top-level configure.in.

# LinuxThreads fragment for GNU C library configure mechanism.
# This is a shell script fragment sourced by the main configure script.

for other in $add_ons; do
  test $other = nptl || continue
  if test $add_ons_automatic = yes; then
    AC_MSG_RESULT($libc_add_on disabled because $other add-on is also in use)
    libc_add_on=
  else
    AC_MSG_ERROR(cannot use both $libc_add_on and $other add-ons in one build)
  fi
done