Resolve gap-system/gap#5761

PackageInfo.g

@@ -79,16 +79,26 @@ Dependencies := rec(
 ),
 
 AvailabilityTest := function()
+  if CompareVersionNumbers("gap", "4.12.1") then
+    if not IsKernelExtensionAvailable("crypting") then
+      LogPackageLoadingMessage(PACKAGE_WARNING,
+                              ["the kernel module is not compiled, ",
+                               "the package cannot be loaded."]);
+      return fail;
+    fi;
+  else
     if Filename(DirectoriesPackagePrograms("crypting"), "crypting.so") = fail then
- 	return fail; 
-    fi;	
-    return true;
+      LogPackageLoadingMessage(PACKAGE_WARNING,
+                              ["the kernel module is not compiled, ",
+                               "the package cannot be loaded."]);
+      return fail;
+    fi;
+  fi;
+  return true;
 end,
 
 TestFile := "tst/testall.g",
 
 #Keywords := [ "TODO" ],
 
 ));
-
-

init.g

@@ -3,10 +3,18 @@
 #
 # Reading the declaration part of the package.
 #
-_PATH_SO:=Filename(DirectoriesPackagePrograms("crypting"), "crypting.so");
-if _PATH_SO <> fail then
+
+if CompareVersionNumbers(GAPInfo.Version, "4.12") then
+  if not LoadKernelExtension("crypting") then
+    Error("failed to load the crypting package kernel extension");
+  fi;
+else
+  # TODO this clause can be removed once Digraphs requires GAP>=4.12.1
+  _PATH_SO:=Filename(DirectoriesPackagePrograms("crypting"), "crypting.so");
+  if _PATH_SO <> fail then
     LoadDynamicModule(_PATH_SO);
+  fi;
+  Unbind(_PATH_SO);
 fi;
-Unbind(_PATH_SO);
 
 ReadPackage( "crypting", "gap/crypting.gd");