should be it

external/duckdb/.github/patches/extensions/README.md

@@ -0,0 +1,42 @@
+# Extension patches
+Patches in this directory are used to smoothen the process of introducing changes to DuckDB that break compatibility with an
+out-of-tree extension. Extensions installed from git urls can automatically apply patches found in this directory. The APPLY_PATCHES flag 
+should be used to explicitly enable this feature. For example,
+lets say our extension config looks like this:
+
+```shell
+duckdb_extension_load(spatial
+    DONT_LINK
+    GIT_URL https://github.com/duckdb/duckdb_spatial
+    GIT_TAG f577b9441793f9170403e489f5d3587e023a945f
+    APPLY_PATCHES
+)
+```
+In this example, upon downloading the spatial extension, all patches in the `.github/patches/extensions/spatial/*.patch`
+will be automatically applied.
+
+Note that the reason for having the APPLY_PATCHES flag explicitly enabled is to make it easier for developers reading
+the extension config to detect a patch is present. For this reason, the patching mechanism will actually fail if `APPLY_PATCHES`
+is set with no patches in `.github/patches/extensions/<ext>/*.patch`.
+
+# Workflow
+Imagine a change to DuckDB is introduced that breaks compatibility with extension X. The
+workflow for this is as follows:
+
+### PR #1: breaking change to DuckDB
+- Commit breaking change to DuckDB
+- Fix breakage in extension X, producing a patch with fix (be wary of already existing patches)
+- Commit patch in `.github/patches/extensions/x/*.patch` using a descriptive name
+- enable APPLY_PATCHES for extension X in `.github/config/out_of_tree_extensions.cmake` (if not already enabled)
+
+### PR #2: patch to extension X
+- Apply (all) the patch(es) in `.github/patches/extensions/x/*.patch` to extension X.
+
+### PR #3: update extension X in DuckDB
+- Remove patches in `.github/patches/extensions/x/*.patch`
+- Remove `APPLY_PATCHES` flag from config
+- Update hash of extension in config
+
+
+
+