testcases/Makefile.PL: tell MakeMaker this is a pure-Perl distribution (#2922)

fixes #2914

diff --git a/testcases/Makefile.PL b/testcases/Makefile.PL
index 0b1f305592a14e806bb5ae4920a1404ed05761f5..bf4e5dd70802c880b29f23e8c544b828df797e2b 100755 (executable)
--- a/testcases/Makefile.PL
+++ b/testcases/Makefile.PL
@@ -18,7 +18,11 @@ WriteMakefile(
     PM => {}, # do not install any files from this directory
     clean => {
         FILES => 'testsuite-* latest i3-cfg-for-*',
-    }
+    },
+    # This is a pure-Perl distribution:
+    linkext => {
+        LINKTYPE => '',
+    },
 );
 
 package MY;