mkdir tmp
cd tmp
../configure --enable-maintainer-mode --enable-build-Xlt
compiling one of the files from libXlt shows:
/bin/sh ../libtool --mode=compile gcc -DHAVE_CONFIG_H -I.
-I../../../../lib/Xlt/
lib -I.. -I../../../include/Motif-2.0
-I../../../../lib/Xlt/../../include/
Motif-2.0 -I../../../include/Motif-1.2
-I../../../../lib/Xl
t/../../include/Motif-1.2 -I/usr/X11R6/include -g -O2 -Wall -c
../../../../
lib/Xlt/lib/NumEntry.c
gcc -DHAVE_CONFIG_H -I. -I../../../../lib/Xlt/lib -I..
-I../../../include/Motif-
2.0 -I../../../../lib/Xlt/../../include/Motif-2.0 -I../../../include/Motif-1.2
-
I../../../../lib/Xlt/../../include/Motif-1.2 -I/usr/X11R6/include -g -O2 -Wall
-
c ../../../../lib/Xlt/lib/NumEntry.c -fPIC -DPIC -o NumEntry.lo
which seems to have both the src and build dirs in the includes.
