Hi Chris, On 2012-02-28 11:33 -0800, Chris Stankevitz wrote: > The following command assigns the variable OPENCV_CFLAGS with "-I > /path/to/opencv/include": > PKG_CHECK_MODULES(OPENCV, opencv >= 2.3.1,, AC_MSG_ERROR(${OPENCV_PKG_ERRORS})) Not directly related to your problem, but you should quote the macro arguments above, as in: PKG_CHECK_MODULES([OPENCV], [opencv >= 2.3.1],, [AC_MSG_ERROR([${OPENCV_PKG_ERRORS}])]) Otherwise, the arguments are subject to macro expansion /before/ they are substituted into the body of PKG_CHECK_MODULES. > Q1: How to I tell AC_CHECK_HEADER to use the include directory > specified in OPENCV_CFLAGS? > > A1: CPPFLAGS="${OPENCV_CFLAGS} $CPPFLAGS" > > Q2: But I thought I wasn't supposed to mess with CPPFLAGS, it was only > for the user to play with. Plus I don't want to affect all CPPFLAGS > for the entire project. I intend to selectively apply OPENCV_CFLAGS > where needed. That is essentially correct, you should allow the user to override CPPFLAGS. For tests like the above, though, you can save/restore the CPPFLAGS (or other similar variables) temporarily. Something like the following (untested) old_CPPFLAGS=$CPPFLAGS CPPFLAGS="${OPENCV_CPPFLAGS} $CPPFLAGS" # do stuff CPPFLAGS=$old_CPPFLAGS should do the trick. Hope that helps, -- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/) _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf