Howdy,

app/xprop uses the macro

AC_CHECK_HEADERS_ONCE

but also indicates the required autoconf version is only 2.57 (AC_PREREQ([2.57]).

AC_CHECK_HEADERS_ONCE was only created in autoconf 2.59c 
(http://cygwin.com/ml/cygwin-apps/2006-06/msg00108.html)

hence building with 2.57 or even 2.59 normal it fails with 

configure.ac:38: error: possibly undefined macro: AC_CHECK_HEADERS_ONCE
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
autoreconf: /usr/bin/autoconf failed with exit status: 1


The fix: don't use _ONCE

root@tinderbox:/mnt/tinder/stage/master/work/app/xprop# git diff
diff --git a/configure.ac b/configure.ac
index 78e4049..62c488e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -35,7 +35,7 @@ XORG_MACROS_VERSION(1.1)
 AC_PROG_CC
 AC_PROG_INSTALL
 
-AC_CHECK_HEADERS_ONCE([wchar.h wctype.h])
+AC_CHECK_HEADERS([wchar.h wctype.h])
 
 # Checks for pkg-config packages
 PKG_CHECK_MODULES(XPROP, x11)

Found By: tinderbox