Another port that has been broken by the png update:

cc  -O2 -pipe -fno-strict-aliasing   -L/usr/local/lib -o dvipdfmx dvipdfmx-agl.o
  dvipdfmx-bmpimage.o dvipdfmx-cff.o  dvipdfmx-cff_dict.o dvipdfmx-cid.o  dvipdf
mx-cidtype0.o dvipdfmx-cidtype2.o  dvipdfmx-cmap.o dvipdfmx-cmap_read.o  dvipdfm
x-cmap_write.o dvipdfmx-cs_type2.o  dvipdfmx-dpxconf.o dvipdfmx-dpxcrypt.o  dvip
dfmx-dpxfile.o dvipdfmx-dpxutil.o  dvipdfmx-dvi.o dvipdfmx-dvipdfmx.o  dvipdfmx-
epdf.o dvipdfmx-error.o  dvipdfmx-fontmap.o dvipdfmx-jpegimage.o  dvipdfmx-mem.o
 dvipdfmx-mfileio.o  dvipdfmx-mpost.o dvipdfmx-numbers.o  dvipdfmx-otl_conf.o dv
ipdfmx-otl_opt.o  dvipdfmx-pdfcolor.o dvipdfmx-pdfdev.o  dvipdfmx-pdfdoc.o dvipd
fmx-pdfdraw.o  dvipdfmx-pdfencoding.o dvipdfmx-pdfencrypt.o  dvipdfmx-pdffont.o
dvipdfmx-pdfnames.o  dvipdfmx-pdfobj.o dvipdfmx-pdfparse.o  dvipdfmx-pdfresource
.o dvipdfmx-pdfximage.o  dvipdfmx-pkfont.o dvipdfmx-pngimage.o  dvipdfmx-pst.o d
vipdfmx-pst_obj.o  dvipdfmx-sfnt.o dvipdfmx-spc_color.o  dvipdfmx-spc_dvips.o dv
ipdfmx-spc_html.o  dvipdfmx-spc_misc.o dvipdfmx-spc_pdfm.o  dvipdfmx-spc_tpic.o
dvipdfmx-spc_util.o  dvipdfmx-specials.o dvipdfmx-subfont.o  dvipdfmx-tfm.o dvip
dfmx-tt_aux.o  dvipdfmx-tt_cmap.o dvipdfmx-tt_glyf.o  dvipdfmx-tt_gsub.o dvipdfm
x-tt_post.o  dvipdfmx-tt_table.o dvipdfmx-truetype.o  dvipdfmx-type0.o dvipdfmx-
t1_char.o  dvipdfmx-t1_load.o dvipdfmx-type1.o  dvipdfmx-type1c.o dvipdfmx-unico
de.o  dvipdfmx-vf.o dvipdfmx-xbb.o    -lpng -lm -lz -lpaper -lkpathsea -lkpathse
a
dvipdfmx-pngimage.o(.text+0x222f): In function `check_for_png':
: undefined reference to `png_check_sig'
*** Error code 1

Stop in /usr/ports/print/dvipdfmx/work/dvipdfmx-20090522/src.
*** Error code 1

Stop in /usr/ports/print/dvipdfmx/work/dvipdfmx-20090522.
*** Error code 1

Stop in /usr/ports/print/dvipdfmx/work/dvipdfmx-20090522.
*** Error code 1

Stop in /usr/ports/print/dvipdfmx.