https://bugs.gentoo.org/929019

--- a/converter/other/pnmtorle.c
+++ b/converter/other/pnmtorle.c
@@ -374,7 +374,7 @@
         if (cmdline.header) {
             skipData(ifP, width, height, maxval, format);
         } else {
-            rle_addhist(argv, NULL, &hdr);
+            rle_addhist((char**)argv, NULL, &hdr);
             writeRleHeader(cmdline.alpha, format, width, height, &hdr);
             writeRleData(verbose, cmdline.alpha, ifP, &hdr,
                          width, height, maxval, format);