[libgda] build: Note we don't support srcdir != builddir

[Colin Walters <walters src gnome org>]

commit 9ec222ed04a46347a29ddc58ffe29bf1933ebe48
Author: Colin Walters <walters verbum org>
Date:   Thu Sep 27 18:52:37 2012 -0400

    build: Note we don't support srcdir != builddir
    
    It blows up somewhere when we're looking for libgda-5.0.pc, which I
    think vala is looking for in $(top_srcdir).

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 84df33d..48c993e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,6 +23,9 @@ AM_INIT_AUTOMAKE([1.11.1 -Wall no-define no-dist-gzip dist-xz])
 
 m4_ifdef([AM_SILENT_RULES],[AM_SILENT_RULES([yes])])
 
+dnl http://people.gnome.org/~walters/docs/build-api.txt
+echo \#buildapi-variable-no-builddir >/dev/null
+
 AC_SUBST(GDA_VERSION, major.minor.micro)
 
 # ABI version: