Just now after
WT-7592 was merged I reran "ninja" in the cmake build dir, and the build failed at the end because of dangling references to WT_SESSION::transaction_sync in the python bindings. Deleting the build directory and rebuilding from scratch worked.
The build reran cmake, but apparently did not rerun swig, so the problem is almost certainly that in the ninja file the swig bindings should depend on something else they currently don't. However, I have no idea how to get cmake to do that.