Make the most painful tasks in regenerate fully incremental [LUCENE-9872]

[asfimport]

This is particularly important for that one jflex task that is currently mood-killer.

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Migrated from LUCENE-9872 by Dawid Weiss (@dweiss), resolved Apr 02 2021
Parent: #10910
Linked issues:

• Verify checksums on generated files [LUCENE-9868] #10907

Pull requests: #60

[asfimport]

Dawid Weiss (@dweiss) (migrated from JIRA)

I filed a pull request. Getting this right (and easy) is surprisingly difficult. I've added checksum validation and skipping to the most problematic pieces (jflex, javacc, moman-derived sources). Works for me. Making it work for everything (binary derived resources) requires jumping through hoops. I think I'm happy with what it is now.

[asfimport]

ASF subversion and git services (migrated from JIRA)

Commit e3ae57a in lucene's branch refs/heads/main from Dawid Weiss
https://gitbox.apache.org/repos/asf?p=lucene.git;h=e3ae57a

LUCENE-9872: Make the most painful tasks in regenerate fully incremental (#60)

[asfimport]

ASF subversion and git services (migrated from JIRA)

Commit 4c2384a in lucene's branch refs/heads/main from Dawid Weiss
https://gitbox.apache.org/repos/asf?p=lucene.git;h=4c2384a

LUCENE-9872: load input/output checksums prior to executing the target task, even if regenerate is not called.

[asfimport]

Adrien Grand (@jpountz) (migrated from JIRA)

Closing after the 9.0.0 release