Hello all, here is some additional context. I think this bug is present in all openjdk versions, not only openjdk-11. It was [recently fixed][1] for openjdk-8 which is [maintained separately][2] from the [repository in salsa][3] which includes openjdk-11 and above.
The affected source of the [post install script][7] for openjdk and later can be found in the salsa repository. The issue is that this script does not check if man1 exits. The FSH standard [requires /usr/bin/man to exists (see FSH 4.11.2)][6], [but not subfolders such as man1 (see FSH 4.11.6 and footnote 32)][5]. This means the openjdk package is not compatible with the FSH. In a docker image this folder does not exists causing the update-alternatives call to fail. A patch has been created recently for openjdk-8 and can be found in commit cfae7df8a6f6710ae97c582a42785c136b0e6f73 of [2]. That commit fixes the issue by adding this line to the post install script: test -d /usr/share/man/man1 || mkdir -p /usr/share/man/man1 I raised a [merge request][4] to port the fix to the salsa repository, so it can be applied to openjdk-11 and later. I hope that helps to fix this issue. Kind Regards Sebastian [1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199#23 [2]: https://evolvis.org/anonscm/git/alioth/openjdk-8.git/ [3]: https://salsa.debian.org/openjdk-team/openjdk [4]: https://salsa.debian.org/openjdk-team/openjdk/-/merge_requests/1 [5]: https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch04s11.html#idm236091735088 [6]: https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch04s11.html [7]: https://salsa.debian.org/openjdk-team/openjdk/-/blob/master/debian/JB-jdk-headless.postinst.in
