RFR: 8282567: Improve source-date handling in build system

[Severin Gehwolf]

On Wed, 2 Mar 2022 16:54:21 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

> To clarify, the end effect of these changes is that building OpenJDK will basically be compliant with the method of just setting SOURCE_DATE_EPOCH. (The caveat is that it must be set at configure time, not build time.) So
> 
> ```
> $ export SOURCE_DATE_EPOCH=123
> $ bash configure
> $ make
> ```

Do you have an example configure output when used like that post-patch?

> will cause the build to default to building in reproducible mode, with the date given by SOURCE_DATE_EPOCH.

Hmm, when building via RPM, `SOURCE_DATE_EPOCH` is usually set. If I understand this correctly, prior to this, the RPM build would be non-reproducible. After it it would be. That may be confusing to some. If post-patch this makes the build reproducible, does it mention that via a WARNING/INFO or anything like that after this patch? I don't see it. Am I missing it? It would be good to have something to that effect in the configure output.

-------------

PR: https://git.openjdk.java.net/jdk/pull/7660