COMP: adjust Allwmake to build scotch-6.0.5a (fixes #31)

- only builds properly in serial.
  Allwmake adjusted accordingly, or simply build with '-j 1'

Allwmake

@@ -100,6 +100,12 @@ then
 elif [ -d "$SCOTCH_SOURCE_DIR" ]
 then
 (
+    # Older versions ok, but scotch-6.0.5a cannot build in parallel.
+    # Force serial build
+    export WM_NCOMPPROCS=1
+    echo "*** building scotch in serial ***"
+    echo
+
     cd $SCOTCH_SOURCE_DIR/src || exit 1
     export GIT_DIR=$SCOTCH_SOURCE_DIR/.git # Mask seeing our own git-repo
     rm -rf $SCOTCH_ARCH_PATH
@@ -169,6 +175,11 @@ then
         echo "    ptscotch library: $FOAM_EXT_LIBBIN/$FOAM_MPI"
     else
     (
+        # Older versions ok, but scotch-6.0.5a cannot build in parallel.
+        # Force serial build
+        export WM_NCOMPPROCS=1
+        echo "*** building pt-scotch in serial ***"
+
         cd $SCOTCH_SOURCE_DIR/src || exit 1
         export GIT_DIR=$SCOTCH_SOURCE_DIR/.git # Mask seeing our own git-repo
         echo

BUILD.md

@@ -457,6 +457,7 @@ that clang compiler for building the newer llvm/clang version.
 
 [page scotch]:    https://www.labri.fr/perso/pelegrin/scotch/
 [link scotch]:    https://gforge.inria.fr/frs/download.php/file/34099/scotch_6.0.3.tar.gz
+[link scotch]:    https://gforge.inria.fr/frs/download.php/file/37398/scotch_6.0.5a.tar.gz
 
 [page kahip]:     http://algo2.iti.kit.edu/documents/kahip/
 [link kahip]:     http://algo2.iti.kit.edu/schulz/software_releases/KaHIP_2.00.tar.gz