gis/saga-gis: Fix build failures.

gis/saga-gis/README

@@ -6,8 +6,11 @@ Functions are organised as modules in framework independent Module Libraries
 and can be accessed via SAGA's Graphical User Interface or various scripting
 environments (shell scripts, Python, R and so on).
 
-SAGA can use these optional dependencies: libharu, opencv, postgresql and
-qhull. SAGA currently does not build when vigra is installed.
+SAGA can use these optional dependencies: libharu, postgresql and qhull. SAGA
+currently does not build when vigra is installed.
+
+To enable opencv, set OPENCV=ON. By default OpenCV is disabled since SAGA does
+not build when OpenCV version 4 or greater is installed.
 
 If SAGA fails to run after an upgrade, uninstall old versions of SAGA before
 compilation.

gis/saga-gis/saga-gis.SlackBuild

@@ -41,17 +41,18 @@ TMP=${TMP:-/tmp/SBo}
 PKG=$TMP/package-$PRGNAM
 OUTPUT=${OUTPUT:-/tmp}
 
+# issues with -O2 causing build failures
 if [ "$ARCH" = "i586" ]; then
-  SLKCFLAGS="-O2 -march=i586 -mtune=i686"
+  SLKCFLAGS="-march=i586 -mtune=i686"
   LIBDIRSUFFIX=""
 elif [ "$ARCH" = "i686" ]; then
-  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
+  SLKCFLAGS="-march=i686 -mtune=i686"
   LIBDIRSUFFIX=""
 elif [ "$ARCH" = "x86_64" ]; then
-  SLKCFLAGS="-O2 -fPIC"
+  SLKCFLAGS="-fPIC"
   LIBDIRSUFFIX="64"
 else
-  SLKCFLAGS="-O2"
+  SLKCFLAGS=""
   LIBDIRSUFFIX=""
 fi
 
@@ -70,6 +71,10 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
   -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+if [ "$OPENCV" != "ON" ] ; then
+  sed -i "s/CVFOUND=1/true/g" configure
+fi
+
 CFLAGS="$SLKCFLAGS" \
 CXXFLAGS="$SLKCFLAGS" \
 PYTHON=python3 \