--- snip ---
checking for pkg-config... /sw/bin/pkg-config
checking for png_read_info in -lpng... no
configure: error: libpng >= 1.2 is needed to compile inkscape
--- snip - no more lines of output from configure ---
This is for a fresh FINK install as per:
http://wiki.inkscape.org/wiki/index.php/CompilingMacOsX
./configure ends without reporting a summary.