Bootstrapping Emacs trunk repeats configure

[Angelo Graziosi <angelo.graziosi@alice.it>]

I notice that bootstrapping recent trunk sources repeats the 'configure' 
while bootstrapping.

For example, with trunk (from git) with timestamps 2014-04-16 
19:43:46-GMT (commit 888f4399e73a231746c9e5bbe9330c898ed94f5e):

$ ./autogen.sh
Checking whether you have the necessary tools...
(Read INSTALL.REPO for more details on building Emacs)

Checking for autoconf (need at least version 2.65)...
ok
Checking for automake (need at least version 1.11)...
ok
Your system has the required tools, running autoreconf...
configure.ac:677: installing 'build-aux/compile'
configure.ac:455: installing 'build-aux/config.guess'
configure.ac:455: installing 'build-aux/config.sub'
configure.ac:103: installing 'build-aux/install-sh'
configure.ac:103: installing 'build-aux/missing'
lib/Makefile.am: installing 'build-aux/depcomp'
You can now run `./configure'.


$ ./configure
checking for xcrun... no
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking build system type... x86_64-unknown-cygwin
checking host system type... x86_64-unknown-cygwin
checking whether we are using GNU Make... yes
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.exe

[...]

Configured for `x86_64-unknown-cygwin'.

   Where should the build process find the source code?    .
   What compiler should emacs be built with?               gcc 
-std=gnu99 -g3 -O2
   Should Emacs use the GNU version of malloc?             yes

[...]

config.status: creating admin/grammars/Makefile
config.status: creating src/config.h
config.status: executing depfiles commands
config.status: executing src/epaths.h commands
config.status: executing src/.gdbinit commands


$ make bootstrap
[ -r "src/config.in" ] || ( cd . && autoheader )
cd src      && make  bootstrap-clean
make[1]: Entering directory '/opt/work/emacs-trunk/src'
rm -f temacs.exe core *.core \#* *.o libXMenu11.a liblw.a
rm -f ../etc/DOC
rm -f bootstrap-emacs.exe emacs-24.4.50.exe
rm -f buildobj.h
rm -f globals.h gl-stamp
rm -f *.res *.tmp
rm -f emacs-*.*.*.exe emacs.exe

[...]

make[1]: Entering directory '/opt/work/emacs-trunk/test/automated'
cd . && rm -f *.elc */*.elc */*/*.elc */*/*/*.elc
make[1]: Leaving directory '/opt/work/emacs-trunk/test/automated'
make[1]: Entering directory '/opt/work/emacs-trunk/admin/grammars'
rm -f Makefile
make[1]: Leaving directory '/opt/work/emacs-trunk/admin/grammars'
make[1]: Entering directory '/opt/work/emacs-trunk/admin/unidata'
if test -f charprop.el; then \
   rm -f `sed -n 's/^;; FILE: //p' < charprop.el`; \
fi
rm -f charprop.el ./*.elc unidata.txt
make[1]: Leaving directory '/opt/work/emacs-trunk/admin/unidata'
[ ! -f config.log ] || mv -f config.log config.log~
rm -rf ./info
rm -f config.cache config.log

cd . && ./autogen.sh
Checking whether you have the necessary tools...
(Read INSTALL.REPO for more details on building Emacs)

Checking for autoconf (need at least version 2.65)...
ok
Checking for automake (need at least version 1.11)...
ok
Your system has the required tools, running autoreconf...
You can now run `./configure'.
make  MAKEFILE_NAME=force-Makefile force-Makefile
make[1]: Entering directory '/opt/work/emacs-trunk'
if [ -x ./config.status ]; then \
      ./config.status --recheck; \
else                            \
      ./configure --cache-file=/dev/null; \
fi

running CONFIG_SHELL=/bin/sh /bin/sh ./configure --no-create --no-recursion
checking for xcrun... no
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking build system type... x86_64-unknown-cygwin
checking host system type... x86_64-unknown-cygwin

[... as above ...]

config.status: creating admin/grammars/Makefile
config.status: creating src/config.h
config.status: executing depfiles commands
config.status: executing src/epaths.h commands
make[2]: Entering directory '/opt/work/emacs-trunk'
make[2]: Leaving directory '/opt/work/emacs-trunk'
config.status: executing src/.gdbinit commands
make[1]: Leaving directory '/opt/work/emacs-trunk'
make  info all

[...]


This 'configure' repetition didn't occur with the trunk of few days ago 
(timestamps 2014-04-11 06:51:49) nor with pretest 24.3.90.

Is all this to be expected?

Thanks,
  Angelo.