When a new patch is recorded, darcs can optionally run a pre-commit
test. The test environment seems to have all patches of the current
repository, even those on which the committed patch does not depend.
Thus, this test cannot detect if a patch is missing dependencies.
Since correct patch dependencies are crucial for effective darcs use,
the test environment should be minimal, and only include the patches
which are pulled in by the dependencies of the patch under test.