Curious error when compiling Garnome 0.25.1

[Boris Goldowsky <boris alum mit edu>]

Is this something to worry about? 

 ==> Running configure in work/main.d/gnome-panel-2.3.3.3
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking whether make sets $(MAKE)... yes
[... lots more output ... ]
checking for gmsgfmt... /usr/bin/msgfmt
checking for xgettext... /usr/bin/xgettext
checking for catalogs to be installed...  am ar az be bg bn ca cs cy da 
de el en_GB eo es et eu fa fi fr ga gl he hu id it ja ko li lt lv mk ml 
mn ms nl nn no pl pt pt_BR ro ru sk sl sq sr sr Latn sv ta tr uk wa vi 
yi zh_CN zh_TW
checking X11/extensions/Xinerama.h usability... no
checking X11/extensions/Xinerama.h presence... yes
configure: WARNING: X11/extensions/Xinerama.h: present but cannot be 
compiled
configure: WARNING: X11/extensions/Xinerama.h: check for missing 
prerequisite headers?
configure: WARNING: X11/extensions/Xinerama.h: proceeding with the 
preprocessor's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to bug-autoconf gnu org  ##
configure: WARNING:     ## ------------------------------------ ##
checking for X11/extensions/Xinerama.h... yes
checking for XineramaQueryScreens in -lXinerama... yes
checking for png_init_io in -lpng... yes
[... more output ... ]

It seems to go ahead and compile despite the warnings.

Bng