bug#14569: 24.3.50; bootstrap fails on Cygwin

[Katsumi Yamaoka]

Hi,

Bootstrap got to fail on Cygwin since yesterday.  An error occurs
at least when performing batch-update-autoloads as follows:

[...]
Wrote /Work/emacs/lisp/mh-e/mh-loaddefs.el
(No changes need to be saved)
EMACSLOADPATH=/Work/emacs/lisp LC_ALL=C /Work/emacs/src/bootstrap-emacs.exe \
 -batch --no-site-file --no-site-lisp -l autoload \
 --eval "(setq generate-autoload-cookie \";;;###tramp-autoload\")" \
 --eval "(setq generated-autoload-file (unmsys--file-name 
\"/Work/emacs/lisp/net/tramp-loaddefs.el\"))" \
 --eval "(setq make-backup-files nil)" \
 -f batch-update-autoloads /Work/emacs/lisp/net
GLib (gthread-posix.c): Unexpected error from C library during 
'pthread_setspecific': Invalid argument.  Aborting.
Makefile:392: recipe for target `/Work/emacs/lisp/net/tramp-loaddefs.el' failed
make[3]: *** [/Work/emacs/lisp/net/tramp-loaddefs.el] Aborted
[...]
make: *** [bootstrap] Error 2

I can run bootstrap-emacs.exe with the -Q option but I have no
clue to examine it.  Please help.

(This is of what I built last.)
In GNU Emacs 24.3.50.1 (i686-pc-cygwin, X toolkit, Xaw3d scroll bars)
 of 2013-06-05 on localhost
Bzr revision: 112848 eliz@gnu.org-20130604163346-bxz8tbdsd4zt5zm2
Windowing system distributor `The Cygwin/X Project', version 11.0.11401000
Configured using:
 `configure --verbose --with-x-toolkit=lucid --without-imagemagick
 --without-dbus --without-gconf --without-gsettings'