Dear sirs --

The software wants me to report a bug.
Here is the transcript of the session.
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555$ darcs record -a -m "Computations for connected 6,3 and 7,3 matroids."
darcs: bug in darcs!
Impossible case at PatchRead.lhs:56 compiled 12:25:14 Jun 24 2006
Please report this to bugs@darcs.net,
If possible include the output of 'darcs --exact-version'.
556$ darcs --exact-version
darcs compiled on Jun 24 2006, at 12:27:50
# configured Sat Jun 24 12:22:49 MST 2006
./configure --no-create --no-recursion

Context:

[TAG 1.0.8
Tommy Pettersson <ptp@lysator.liu.se>**20060616160213]
557$

Seems like a duplicate of issue415.  Thanks.
(It would be interesting to see if you could (1) reproduce this with 1.0.8, i.e.
if you have the problematic case still lying around (2) reproduce it with 1.0.9
as well)

From reviewing the code myself, this issue is "resolved-in-unstable" because the
"impossible case" has been eliminated from the code in Patch/Read.lhs. If you
find a similar issues exists with the Darcs 2 pre-releases, please let us know.