diff -up cmake-3.20.4/Source/kwsys/testDynamicLoader.cxx.libdl cmake-3.20.4/Source/kwsys/testDynamicLoader.cxx
--- cmake-3.20.4/Source/kwsys/testDynamicLoader.cxx.libdl	2021-06-14 10:05:49.000000000 -0500
+++ cmake-3.20.4/Source/kwsys/testDynamicLoader.cxx	2021-06-18 14:17:50.990852438 -0500
@@ -8,6 +8,13 @@
 #  include <be/kernel/OS.h> /* disable_debugger() API. */
 #endif
 
+#ifdef __linux__
+#include <gnu/lib-names.h>
+#ifndef LIBDL_SO
+#define LIBDL_SO "libdl.so.2"
+#endif
+#endif
+
 // Work-around CMake dependency scanning limitation.  This must
 // duplicate the above list of headers.
 #if 0
@@ -107,8 +114,8 @@ int testDynamicLoader(int argc, char* ar
   // This one is actually fun to test, since dlopen is by default
   // loaded...wonder why :)
   res += TestDynamicLoader("foobar.lib", "dlopen", 0, 1, 0);
-  res += TestDynamicLoader("libdl.so", "dlopen", 1, 1, 1);
-  res += TestDynamicLoader("libdl.so", "TestDynamicLoader", 1, 0, 1);
+  res += TestDynamicLoader(LIBDL_SO, "dlopen", 1, 1, 1);
+  res += TestDynamicLoader(LIBDL_SO, "TestDynamicLoader", 1, 0, 1);
 #endif
   // Now try on the generated library
   std::string libname = GetLibName(KWSYS_NAMESPACE_STRING "TestDynload");