If you're on the main branch, the code to regenerate ICU is in lucene.regenerate.icu.gradle:
https://github.com/apache/lucene/blob/main/build-tools/build-infra/src/main/groovy/lucene.regenerate.icu.gradle#L4 you should bump the version of icu4j and this makes the build use the aligned icu-c version too - https://github.com/apache/lucene/blob/main/gradle/libs.versions.toml#L24 Once you do that, run: ./gradlew -p lucene/analysis/icu regenerate and it should regenerate, clean-up and create checksums for all affected files. - Why aren't we generating them on the fly based on the available ICU > version at runtime? Would that enable users to upgrade ICU versions on > their own without breaking Lucene? > The reasons for not generating them on the fly are multiple - mainly we're trying to save on build times (some of the generated resources are very costly or require external tools and infrastructure) but also ensure consistency and catch any changer if they happen in the middleware toolchain somewhere (in theory, if you run the regenerate command above without touching ICU versions, you should get identical checksums of all the resulting files, regardless of the platform used, etc.) Dawid
