I've just tried DVC.
Stefan, could you apply this patch to your tree.
It seems that I cannot run diff on dvc even with baz.
dvc is still not stable enough to develop dvc itself:-P
--- orig/lisp/xtla.el
+++ mod/lisp/xtla.el
@@ -2835,7 +2835,7 @@
LAST-REVISION looks like
\(\"path\" NUM)."
(when (not (eq (nth 1 last-revision) 1))
- (error "TODO. revision=%S" revision))
+ (error "TODO. revision=%S" last-revision))
(let* ((default-directory (car last-revision)))
(tla-revision-get-last-or-file-revision file nil t)))
