I can't tell you on linux, but on windows, open
contrib/ports/win32/msvc6/test.dsw or ../msvc8/lwIP_Test.sln and run it
(after adding the missing config file lwipcfg_msvc.h from _example).
That brings you a running lwIP system where you can enable the
httpserver_raw app.
What is the folder hierarchy requirement for the Win32 example? When
checking out from CVS to a folder, the MSVC6 sln doesn't build as-is.
Maybe
the question is, where does the $(lwip) definition get set as I suspect this
is the issue.