+## Building on macOS/arm64
+
+Build `osx-environment` in `$HOME`
+```
+bash platform/osx/copy_resources.sh
+source platform/osx/set_paths.sh
+./waf configure --target-macos-arm64
+```
+
+
+## Disk writer logging
+
+As we have no `film' folder to log to during disk writes, the logs end up:
+
+### macOS
+
+* Disk writer backend: `/var/log/dcpomatic_disk_writer_{out,err}.log`
+* Disk writer frontend: `/Users/$USER/Library/Preferences/com.dcpomatic/2/2.16/disk.log`
+
+### Windows
+
+* Disk writer backend: `c:\Users\$USER\AppData\Local\dcpomatic\2.16.0\disk_writer.log`
+* Disk writer frontend: `c:\Users\$USER\AppData\Local\dcpomatic\2.16.0\disk.log`
+
+### Linux
+
+* Disk writer backend: `/home/$USER/.config/dcpomatic/2.16.0/disk_writer.log`
+* Disk writer frontend: `/home/$USER/.config/dcpomatic/2.16.0/disk.log`
+
+
+## Branches
+
+The main dcpomatic repo has the following branches:
+
+* `main` - the main development branch; contains 2.16.x versions
+* `v2.17.x` - development branch for v2.17.x versions; `main` is merged into this branch.
+
+The `test/data` submodule has the following branches:
+
+* `v2.16.x` - branch for use with v2.16.x versions
+* `v2.18.x` - branch for use with v2.17.x versions (as will become v2.18.x)
+
+