From c62785b03e6694f5fe2bc631311abcaa9caa8358 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Sat, 23 May 2026 10:20:11 -0400
Subject: [PATCH] README.md + notes on manual git subtree stuff

---
 README.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/README.md b/README.md
index 7468ae11..10883c1e 100644
--- a/README.md
+++ b/README.md
@@ -282,3 +282,15 @@ $ git fetch xo-foo main
 ```
 $ git subtree add --prefix=xo-foo xo-foo main
 ```
+
+## Manual git subtree workflow
+
+walk repo history (slow!), extracting all commits that touched prefix (e.g. `xo-foo`),
+synthesize a standalone commit history as if `xo-foo` were its own repo
+(i.e. strip prefix from all paths).
+
+With `-b _demux/xo-foo` stores thhat tip as local branch
+
+```
+$ git subtree split --prefix=xo-foo -b _demux/xo-foo --rejoin
+```