Description of problem:
Old version of libPNG prevents build of TeX Live 2011 because it uses PNG_FP_1 symbol which is used since 1.5.x and on:
texk/web2c/luatexdir/image/writepng.w:585:19: error: 'PNG_FP_1' undeclared (first use in this function)
Latest stable libpng
Note that libpng-1.5.2 was released 10th Apr 2011:
1.5 is not stable in my opinion, and even if it was, surely TeX ought to be compilable against libpng versions that are in the wild. I think this is a TeX bug.
Reported this at TeX Live mailing list and it is now fixed in TeX Live upstream:
In any case leaving this bug open as RFE. Thanks.
*** This bug has been marked as a duplicate of bug 609234 ***