It took some bash tracing to fill out that* command,* but once that was done, it was obvious that the server was doing exactly what
had been suggested above: trying to listen (bind(2) call) on 0.0.0.0:80 as well as my.host:80.
I had not touched my configs in ages, so I guess some default snuck in there somehow; I suspect something to do with virtual hosts (which I do not need), but it was easy to find and fix.* Now it comes up and serves my pages.
However, my configs contain a few ScriptAlias directories, which are full of python programs.* They are not being executed, but
served up in source code form, even though they have an initial shebang and remain executable by all.* So there must be some new thing to do besides defining a ScriptAlias directory.* Anybody know what it is?