Rebuild Apache HTTP Components Core 5.0.2 (Maven build with toolchain)

[hboutemy]

https://github.com/apache/httpcomponents-core
WIP buildspec: https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/wip/httpcore-5.0.2.buildspec
looks like release 5.0.2 has been built with Maven running with JRE 8, with toolchain using JDK 7 for compiler
but remains some .class that could not be reproduced (even less that with JDK 8 for compiler)

even rebuilding manually on local computer is hard (because of compiler not producing same .class: everything else seems reproducible)

then rebuilding easily with Docker is even harder because in addition there is no prebuilt image with 2 JDKs and toolchain configured: but automation is expected to be a next step once manual works...

[hboutemy]

same toolchain requirement with log4j 2.17.2, that even fails the build if not used with toolchain
WIP buildspec: https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/wip/log4j-1.2.17.buildspec