Document preclean

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/nailing-cargo b/nailing-cargo
index 61184872ec3c00458bd4552f1de9c69dc125b3c1..74516b23ca2d1cfa681923fb38782d0efd3fc722 100755 (executable)
--- a/nailing-cargo
+++ b/nailing-cargo
@@ -27,7 +27,8 @@ options:
   -h --help                       Print this message
   --doc --man --manual            Display complete manual (in w3m)
   --leave-nailed                  Leave the nailed Cargo.toml in place
-  --just-linkfarm | --clean-linkfarm | --keep-linkfarm (default)
+  --just-linkfarm | --clean-linkfarm | --keep-linkfarm (default is keep)
+  --[no-]preclean-linkfarm[=no|src|full]               (default is no)
   --just-run                      Run the command, don't do cargo stuff
   --no-nail                       Do not nail, just run the command.
   --no-cargo-lock-manip           Do not manipulate Cargo.lock.