cvs log: incorrect usage?

[coach24]

If my repository is /usr/local/cvs, am I not supposed to be able to do
this:

cvs log /usr/local/cvs/project/file.py,v

I get the *PANIC* administration files missing error every time.  There
is a CVS directory for that project.  This command doesn't work on two
different machines in three different repositories.  What gives?

Now, if the cvs log command is only supposed to be used in checked out
sandboxes, fine.  What can I do then to be able to parse repository
files for tags?

Thanks for your help,
Bob

PS cvs history on the same pathname works just fine.