This directory is only built if you specify "--with-newlib" at configure
time.

$ mkdir hurd-l4-build
$ cd hurd-l4-build
$ ../hurd-l4/configure [...] --with-newlib
$ make



Reentrancy
----------

newlib has a per-thread reentry structure.  We store a pointer to this
structure in a thread's UTCB in slot _L4_UTCB_THREAD_WORD0.  See
addon/newlib/libc/sys/hurd/getreent.c for details.

errno
-----

Getting newlib to use a different errno location from that in its
errno structure isn't easy: it's hard-wired all over the
implementation.  Since the Hurd's run-time assigns to errno as well
(see libhurd-mm/mmap.c and libhurd-mm/sbrk), to ensure correctness,
they both need to use the same errno location.  This requires that
libhurd-mm be compiled against Newlib's header files.