gd2 @2.1.0 does not contain gdImagePngPtr symbol

[KurtPfeifle (Kurt Pfeifle)]

My attempt to run 'port -p upgrade libgphoto2' failed. The following lines are in the log:

libtool: link: ( cd ".libs" && rm -f "smal.la" && ln -s "../smal.la" "smal.la" )
/bin/sh ../libtool  --tag=CC   --mode=link /usr/bin/clang  -pipe -Os -arch x86_64 -Wall -g -Wmissing-declarations -Wmissing-prototypes -module -no-undefined -avoid-version -export-dynamic -export-symbols '../camlibs/camlib.sym' -rpath '
/opt/local/lib/libgphoto2/2.5.2' -Wl,-headerpad_max_install_names -arch x86_64 -g -o sony_dscf55.la  sonydscf55/sony.lo sonydscf55/camera.lo ../libgphoto2/libgphoto2.la ../libgphoto2_port/libgphoto2_port/libgphoto2_port.la  
libtool: link: ( cd ".libs" && rm -f "samsung.la" && ln -s "../samsung.la" "samsung.la" )
Undefined symbols for architecture x86_64:
  "_gdImageCreateFromPngPtr", referenced from:
      _put_file_func in library.o
  "_gdImagePngPtr", referenced from:
      _get_file_func in library.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [ax203.la] Error 1

[KurtPfeifle (Kurt Pfeifle)]

main.log for failed upgrade of libgphoto2

[KurtPfeifle (Kurt Pfeifle)]

The port for 'dvipng' shows a very similar error: ticket #40126

[ryandesign (Ryan Carsten Schmidt)]

Duplicate of #40123.