START_TEST uses the variable name _i, so GCC complains about redefining it with
a different type here.

--- mc-4.8.28/tests/lib/strutil/filevercmp.c	2022-03-20 10:02:47.000000000 +0000
+++ mc-4.8.28/tests/lib/strutil/filevercmp.c	2022-03-27 15:31:19.812120141 +0100
@@ -353,20 +353,20 @@
 START_TEST (filevercmp_test5)
 /* *INDENT-ON* */
 {
-    size_t _i;
+    size_t ii;
 
-    for (_i = 0; _i < filevercmp_test_ds5_len; _i++)
-        for (; filevercmp_test_ds5[_i] != NULL; _i++)
+    for (ii = 0; ii < filevercmp_test_ds5_len; ii++)
+        for (; filevercmp_test_ds5[ii] != NULL; ii++)
         {
-            const char *i = filevercmp_test_ds5[_i];
-            size_t _j;
+            const char *i = filevercmp_test_ds5[ii];
+            size_t jj;
 
-            for (_j = _i; filevercmp_test_ds5[_j] != NULL; _j++)
+            for (jj = ii; filevercmp_test_ds5[jj] != NULL; jj++)
             {
-                const char *j = filevercmp_test_ds5[_j];
+                const char *j = filevercmp_test_ds5[jj];
 
-                ck_assert_int_eq (test_filevercmp (i, j), 0);
-                ck_assert_int_eq (test_filevercmp (j, i), 0);
+                ck_assert_int_eq (test_filevercmp (i, j), 0);
+                ck_assert_int_eq (test_filevercmp (j, i), 0);
             }
         }
 }