http://snapshot.debian.org/mr/package/clive/ lists 2.2.7-1 but
http://snapshot.debian.org/mr/package/clive/2.2.7-1/srcfiles is a 404.
Looking at http://snapshot.debian.org/package/clive/2.2.7-1/ shows that only
the binary files for that version exist.

I looked into this briefly when you mentioned it on IRC.  The last URL
of yours links to
http://snapshot.debian.org/archive/debian/20091101T105451Z/pool/main/c/clive/
which shows that there are sources, but for some reason they have not
been index properly.

I need to investigate some more but haven't had the time for that yet.

# You merged it to the wrong bug.  Please don't do that.
unmerge 587217
clone 587217 -1

# Also, debsnap not handling a 404 in a place where it's documented to be
# legal is still a debsnap bug.
reassign 587217 debsnap
merge -1 587238
thanks

Ok, The issue is triggered by the package-file.map file containing
entries of these files before the files themselves exist in the mirrored
and imported tree.

That causes the linking between the file and a source or binary package
to fail.

On the next mirrorrun's indexing however, the package-file.map entry is
not considered anymore (in --quick mode) because it was already in the
previous map file.

(For now, I've re-run some mirrorrun's index runs in non-fast mode.
Now ever .dsc file belongs to a src package, and every .deb is
associated with a binary package.)