Well, I got the mercurial version of wget to build (and look at).
README.checkout talks about subversion, and autogen.sh (which isn't there,
I did an autoreconf).
Also, there's a GNUmakefile in the repository -- I guess its not necessary
to build (so we can configure in other directories).
It seems the man page is generated in the build directory...
But it tries to install the man page out of the source directory...
In doc/Makefile:
install.man: $(MAN)
$(top_srcdir)/mkinstalldirs $(DESTDIR)$(mandir)/man$(manext)
$(INSTALL_DATA) $(srcdir)/$(MAN)
