darcs-test -r acts strangely. First this is the help output (lines
starting with # are my comments):

ben@sarun[1]: .../darcs/screened > ./dist/build/darcs-test/darcs-test
--help    
The config program
# huh?

config [OPTIONS]
# Ok looks as if we forgot to specify a name for the program
# so it uses some library default

Common flags:
#...
  -r --repoformat=FORMAT            Repo formats to test (darcs-1, darcs-2).

So I said:

ben@sarun[1]: .../darcs/screened > ./dist/build/darcs-test/darcs-test -r
darcs-1
Could not read, expected one of: darcs1 darcs2

Hmmm. Ok, help text not up-to-date. Next try:

ben@sarun[1]: .../darcs/screened > ./dist/build/darcs-test/darcs-test -r
darcs1
Using darcs executable in
/home/ben/src/darcs/screened/dist/build/darcs/darcs
Locale encoding is UTF-8
EXAMPLE.sh (Darcs2) (PatienceDiff): [Success]
EXAMPLE.sh (Darcs1) (PatienceDiff): [Success]
add-formerly-pl.sh (Darcs2) (PatienceDiff): [Success]
add-formerly-pl.sh (Darcs1) (PatienceDiff): [Success]
[...]

I said darcs-1 but it does the darcs-2 tests also (apparently, judging
from the output).

How do I tell it I want to run only the darcs-1 tests?

Let's see what happens when we spedify darcs-2:

ben@sarun[1]: .../darcs/screened > ./dist/build/darcs-test/darcs-test -r
darcs2 
Using darcs executable in
/home/ben/src/darcs/screened/dist/build/darcs/darcs
Locale encoding is UTF-8
EXAMPLE.sh (Darcs2) (PatienceDiff): [Success]
EXAMPLE.sh (Darcs2) (PatienceDiff): [Success]
[...]

Does this means it runs all tests twice now?

Some of the strangeness seems to follow a pattern. If I tell it to use
darcs1 and darcs2 I three tests are run:

ben@sarun[1]: .../darcs/screened > ./dist/build/darcs-test/darcs-test -r
darcs2 -r darcs1 --tests=issue2382
Using darcs executable in
/home/ben/src/darcs/screened/dist/build/darcs/darcs
Locale encoding is UTF-8
issue2382-mv-dir-to-file-confuses-darcs.sh (Darcs2) (PatienceDiff):
[Success]
issue2382-mv-dir-to-file-confuses-darcs.sh (Darcs2) (PatienceDiff):
[Success]
issue2382-mv-dir-to-file-confuses-darcs.sh (Darcs1) (PatienceDiff): [Failed]

Apparently the repo format option is a list and the default is
["darcs2"] and anything you specify on the command line simply gets
appended to the list.

The following patch sent by Ben Franksen <benjamin.franksen@helmholtz-berlin.de> updated issue issue2457 with
status=resolved;resolvedin=2.12.0 HEAD

* resolve issue2457 
Ignore-this: bd58f81f833e57632ef4b8df4b1681be

- replaced --diffalgorithm with single flags --myers/-m and --patience/-p
- replaced --repoformat with single flags --darcs1/-1 and --darcs2/-2
- document default values in the help text (where applicable)