mysql50 fails to compile on 4.11

[Alexander Kirillov]

Hi all,
mysql50 fails to compile on 4.11 -

libtool15: link: cannot find the library `../zlib/libz.la' or unhandled 
argument `../zlib/libz.la'

What might be wrong here? Is there a workaround of some sort?
TIA,
Sasha