Hello.

Trying to boostrap and build Guile from the master branch of its git
repository fails for me on Debian GNU/Linux:

  $ (set -x && ./autogen.sh && ./configure && cat config.log && make) 2>&1 | tee output
  + ./autogen.sh

  autoconf (GNU Autoconf) 2.68
  Copyright (C) 2010 Free Software Foundation, Inc.
  ...
  ... [MEGA-SNIP]
  ...
  CC     libguile_2.2_la-weak-table.lo
  weak-table.c: In function 'move_disappearing_links':
  weak-table.c:164:7: warning: passing argument 1 of 'GC_unregister_disappearing_link'
  from incompatible pointer type [enabled by default]
  /usr/include/gc/gc.h:771:12: note: expected 'void **' but argument is of type 'scm_t_bits *'
  weak-table.c:165:7: warning: passing argument 1 of 'GC_general_register_disappearing_link'
  from incompatible pointer type [enabled by default]
  /usr/include/gc/gc.h:744:12: note: expected 'void **' but argument is of type 'scm_t_bits *'
  weak-table.c:175:7: warning: passing argument 1 of 'GC_unregister_disappearing_link'
  from incompatible pointer type [enabled by default]
  /usr/include/gc/gc.h:771:12: note: expected 'void **' but argument is of type 'scm_t_bits *'
  weak-table.c:176:7: warning: passing argument 1 of 'GC_general_register_disappearing_link'
  from incompatible pointer type [enabled by default]
  /usr/include/gc/gc.h:744:12: note: expected 'void **' but argument is of type 'scm_t_bits *'
    CC     libguile_2.2_la-weak-vector.lo
    CC     dynl.lo
    CC     posix.lo
    CC     net_db.lo
    CC     socket.lo
    CC     regex-posix.lo
    CCLD   libguile-2.2.la
    CC     guile-guile.o
    CCLD   guile
  ./.libs/libguile-2.2.so: undefined reference to `GC_gcollect_and_unmap'
  ./.libs/libguile-2.2.so: undefined reference to `GC_get_unmapped_bytes'
  collect2: ld returned 1 exit status
  make[3]: *** [guile] Error 1
  make[3]: Leaving directory `/devel/stefano/src/gnu/guile/libguile'
  make[2]: *** [all] Error 2
  make[2]: Leaving directory `/devel/stefano/src/gnu/guile/libguile'
  make[1]: *** [all-recursive] Error 1
  make[1]: Leaving directory `/devel/stefano/src/gnu/guile'
  make: *** [all] Error 2

Attached is the captured output (compressed).  Let me know if you neeed
more information.

Regards,
  Stefano