Does this patch help? By setting HAVE_OBJCOPY=no the build generates
C files as intermediaries.
Index: Makefile
===================================================================
RCS file: ports/textproc/mupdf/Makefile,v
retrieving revision 1.92
diff -u -p -r1.92 Makefile
--- Makefile 17 Sep 2019 09:22:51 -0000 1.92
+++ Makefile 8 Dec 2019 16:43:47 -0000
@@ -72,6 +72,11 @@ WANTLIB += GL glut
LIB_DEPENDS += graphics/freeglut
.endif
+# ld.bfd -r -b binary does not produce correct type of object.
+.if (${MACHINE_ARCH} == "mips64" || ${MACHINE_ARCH} == "mips64el")
+MAKE_FLAGS += HAVE_OBJCOPY=no
+.endif
+
post-install:
${INSTALL_DATA_DIR} ${PREFIX}/share/{applications,pixmaps}
${INSTALL_DATA} ${FILESDIR}/mupdf.xpm ${PREFIX}/share/pixmaps/
