cleanup modulefile

- do not set LD_LIBRARY_PATH on OSX
- set LIBRARY_PATH also when dynamic libraries are disabled

src/lib/modulefile.in

@@ -30,10 +30,16 @@ prepend-path  PATH               $bindir
 prepend-path  CPATH              $includedir
 prepend-path  INCLUDE            $includedir
 
+# library path, can also be useful when soext is not defined in order to link lib$progname.a
+prepend-path  LIBRARY_PATH       $libdir
+
 # path for VIM syntax
 setenv        PLUMED_VIMPATH     $libdir/$progname/vim
 
-# paths for libraries are only set if plumed is compiled as a dynamic library
+# path for pkgconfig
+prepend-path  PKG_CONFIG_PATH    $libdir/pkgconfig/
+
+# some paths are only set if plumed is compiled as a dynamic library
 if { [ string length $soext ]  != 0 } {
 
 # this is checking if PLUMED_KERNEL is already set
@@ -42,10 +48,15 @@ if { [module-info mode load] && [ info exists ::env(PLUMED_KERNEL) ] } {
     puts stderr " (typically means that you are loading two plumed modules, both defining dynamic libraries)"
 }
 
-# library path
-prepend-path  LIBRARY_PATH       $libdir
-prepend-path  LD_LIBRARY_PATH    $libdir
+# ld_library_path is only set on Linux
+if { $soext == "so"  } {
+  prepend-path  LD_LIBRARY_PATH    $libdir
+}
+
+# python path
 prepend-path  PYTHONPATH         $libdir/$progname/python
-prepend-path  PKG_CONFIG_PATH    $libdir/pkgconfig/
+
+# plumed kernel
 setenv        PLUMED_KERNEL      $libdir/lib${progname}Kernel.$soext
+
 }