The current imagemagick ebuild contains the lines #bug 69705 rm -f ${D}/usr/lib/libltdl* , that prevent overwriting libtool's files. But on amd64 those are in /usr/lib64/. Reproducible: Always Steps to Reproduce: 1. 2. 3.
Created attachment 66439 [details, diff] imagemagick-libtool-amd64.diff Seems to work ok, tested in my x86 and in pitr.
Replacing rm -f ${D}/usr/lib/libltdl* with rm -f ${D}/usr/$(get_libdir)/libltdl* would be the best way to patch the ebuilds. econf gets the lib directory from the same source as the function and so it should always work as expected.
It's fixed by upstream in 6.2.4.2, which was just added to portage.