Problem exists only in plotutils-2.4.1-r3.ebuild. It only affects k6, k6-2, and k6-3 users. It appeared when someone converted a bunch of sed statements to replace-cpu-flags. It could have also been caused by a syntax change to replace-cpu-flags, but I'm not sure. Patch is attached.
*** This bug has been marked as a duplicate of 115242 ***