CPSolver 1.2_bld46: source, build, and replacement

This guide locates the CPSolver source and explains how to rebuild and replace its library. It is for users running the course-timetabling task or distributing its Java dependencies.

The course-timetabling online and offline tasks use environment/app/lib/cpsolver-all-1.2.jar. Its SHA-256 is 73d4b2e866ddf3646cd29db919675ed49b6425873ed4b92f63a81df669b12366; the JAR reports version 1.2_bld46 and release date 2011-05-13.

Obtain the pinned source

The official UniTime/cpsolver release commit is CPSolver build 46. Download and verify that source archive:

curl -fL --retry 3 \
  https://codeload.github.com/UniTime/cpsolver/tar.gz/e2a59acaec364748bebd415f642eb16ee47dc274 \
  -o cpsolver-1.2_bld46-source.tar.gz
echo '205bc712f28f013858657e535cec001e00e5450420357576ba683c50d854b77a  cpsolver-1.2_bld46-source.tar.gz' | sha256sum -c -
tar -xzf cpsolver-1.2_bld46-source.tar.gz

Build

Building requires Python 3 and a JDK that supports javac --release 8 (tested with JDK 21). From the repository root, substitute the extracted source and desired output paths:

python3 assets/environments/cpsolver/build_cpsolver_core.py \
  /path/to/cpsolver-e2a59acaec364748bebd415f642eb16ee47dc274 \
  /path/to/cpsolver-rebuilt.jar

The build script compiles in a temporary directory and refuses to overwrite an existing output. The upstream commit's build.number is 47; the script sets it to 46 to match the task JAR. Algorithm source is unchanged. The original Ant files target Java 5/6; this script produces Java 8-compatible classes.

The rebuilt JAR has different bytes from the task JAR. The build record contains the public-interface comparison. Run task-level checks after replacing the library, and report the replacement when publishing evaluation results.

Replace the library

In a copy of a task working directory, put the rebuilt JAR at lib/cpsolver-all-1.2.jar, keep dom4j and log4j beside it, and rerun that copy's build.sh. The wrapper loads libraries from classes:lib/*; it imposes no signature check or fixed JAR hash. Keep the original JAR for runs intended to reproduce the benchmark.

The core Java source is LGPL-3.0-or-later; original Ant files carry LGPL-2.1-or-later notices. Distribution of the binary must include its corresponding source and build materials, the LGPL text, the GPL text, and the original dom4j notice and log4j terms. Retain the applicable notice on each corresponding source file.