dgit-maint-debrebase(7): Add runes for inspecting history

I'm not sure if this is the right place but I wanted to publish this
information sooner rather than later.

Closes: #907190.

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

1 files changed, 47 insertions, 0 deletions

diff --git a/dgit-maint-debrebase.7.pod b/dgit-maint-debrebase.7.pod
index 16b65b3..b4330f9 100644
--- a/dgit-maint-debrebase.7.pod
+++ b/dgit-maint-debrebase.7.pod
@@ -458,6 +458,53 @@ Note that this will introduce a new pseudomerge.
 After dgit pushing, be sure to git push to B<salsa.debian.org>, if
 you're using that.
 
+=head1 INSPECTING THE HISTORY
+
+The git history made by git-debrebase can seem complicated.
+Here are some suggestions for helpful invocations of gitk and git.
+They can be adapted for other tools like tig, git log, etc.
+
+=over
+
+=item History of package in Debian (disregarding history from upstream):
+
+    % gitk --first-parent
+
+In a laundered branch, the delta queue is at the top.
+
+=item History of the packaging (excluding the delta queue)
+
+    % gitk :/debian :!/debian/patches
+
+=item Just the delta queue (ie, Debian's changes to upstream):
+
+    % gitk --first-parent -- :/ :!/debian
+
+=item Full history including old versions of the delta queue:
+
+    % gitk --date-order
+
+The "Declare fast forward" commits you see have an older history
+(usually, an older delta queue) as one parent,
+and a newer history as the other.
+--date-order makes gitk show the delta queues in the right order.
+
+=item Show complete diff since the last upload:
+
+    % git diff dgit/dgit/sid..HEAD -- :/ :!/debian/patches
+(Includes changes to upstream files.)
+
+=item Interdiff of delta queue since last upload, if you really want that:
+
+    % git debrebase make-patches
+    % git diff dgit/dgit/sid..HEAD -- debian/patches
+
+=back
+
+Also of course there is
+
+    % git debrebase status
+
 =head1 HANDLING DFSG-NON-FREE MATERIAL
 
 =head2 Illegal material