Darcs convert, when supplied with a non-existent repository name, spits
out a pattern match failure instead of reporting the error properly:

$ /usr/bin/darcs --version
2.4.4 (release)
$ /usr/bin/darcs convert noname00.pas

darcs failed:  Pattern match failure in do expression at
src/Darcs/Commands/Convert.lhs:134:2-13

I think I fixed this in one line of code, as the appropriate error
message was already there, going to submit a patch soon:

$ darcs --version
2.4.98.5 (+ 277 patches)
$ darcs convert noname00.pas

darcs failed:  Not a repository: noname00.pas
(noname00.pas/_darcs/inventory: openBinaryFile: does not exist (No such
file or directory))

Note: I was expecting to find a _darcs/inventory file because I could
not find (or read) _darcs/format and assumed that the remote repository
is old-fashioned.

The following patch sent by Dmitry Tsygankov <dmitry.tsygankov@gmail.com> updated issue issue1984 with
status=resolved;resolvedin=2.8.0 HEAD

* resolve issue1984: better error message for 'darcs convert' 
Ignore-this: 1e1112dba335510460cffd8c377fe776