This will not affect configurations where a prebuilt ninja is available in the search path (like most of CI) -- in this case we only require its version to be 1.8.2 or newer.
We are planning to proceed with the update next week, so to give a chance to users and downstream adopters to assess the change in advance.
We have now updated to Ninja 1.13.1 for main, rebranch and next schemes.
If you encounter any issue as a result of the upgrade, please file a new issue with the build-script label and with the following information
full builld log (possibly by running build-script with -v)
relevant build.ninja and .ninja_deps file from the affected build folder -- you can find those from find the last ninja or cmake --build invocation, and checking on the above lines the current directory we moved in