My remote server went down earlier so I couldn't push to the
main repository.  Someone else needed a patch I had just
made, so I tried sending it with "darcs send --to addr" but
I get:

darcs failed:  Not a repository:  (/_darcs/inventory: openBinaryFile: does not exist (No such file or directory))

So I just decided to wait, but now that the server is back
up I can't push anymore:

chernushka:hato$ darcs push
darcs: bug in darcs!
Empty filename in is_relative
Please report this to bugs@darcs.net,
If possible include the output of 'darcs --exact-version'.

chernushka:hato$ darcs --exact-version
darcs compiled on Oct  6 2007, at 14:09:30
# configured Sat Jun 16 09:59:48 PDT 2007
./configure /usr/local/share/config.site /usr/local/etc/config.site

Context:

[TAG 1.0.9
Tommy Pettersson <ptp@lysator.liu.se>**20070603213706]

These bugs are fixed in the unstable branch of darcs. 

The workaround is to give the Repo URL when you are using darcs send, or again
when you are using "darcs push".