Config: native 'SOURCE_DATE_EPOCH' pattern-replacement support #13538
Conversation
… discussion-13526/copyright-patterns-support-source-date-epoch
Relates-to commit de4af25.
… discussion-13526/copyright-patterns-support-source-date-epoch
…t-source-date-epoch
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don't worry about merging master, it takes up CI resource, we have a limit of ~15(?) concurrent jobs on the whole organisation |
| """ | ||
| system_time = time.localtime() | ||
| if (source_date_epoch := getenv('SOURCE_DATE_EPOCH')) is not None: | ||
| if (rebuild_time := time.localtime(float(source_date_epoch))) < system_time: |
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Note: in gettext.py, previously SOURCE_DATE_EPOCH was used in combination with time.gmtime (UTC-relative), instead of time.localtime (system-local-timezone relative).
I will admit that one aspect of using localtime here is that it required significantly less adjustment to the test suite. That's not a great reason to adjust it, though.
I do think that strictly speaking, time.localtime provides the most flexibility for users -- although it does open up the quirk/oddity that some dates close to the start/end of the year could flip between years if people are not careful to set a constant timezone alongside their SOURCE_DATE_EPOCH.
However: if someone does want to create reproducible documentation, and legitimately wants to fix their timezone to their location (or the location of their organization, or the place where the printer is going to spool their printout, or whatever), then I think allowing a combination of TZ (e.g. time.localtime) alongside SOURCE_DATE_EPOCH is the way to go.
Purpose
Sphinx provides support for a
%Yyear-substitution pattern that dynamically places the publication year into thecopyrightandproject_copyrightconfiguration settings.Additionally, we attempt to support reproducible builds when possible, using the
SOURCE_DATE_EPOCHenvironment variable.Previously, it was possible in some cases for
%Yvalues to be replaced with reproducible output when the settings produced byevaluate_copyright_placeholderswere compatible with the patterns matched by the subsequently-runcorrect_copyright_yearmethod. In particular, this required use of ASCII hyphens as year-range separators (e.g.2000-%Ywould accept and allow publication year replacement since it uses an ASCII hyphen, but2000–%Ywould not, because that latter string uses an en-dash character as the range indicator).To remove the requirement that these two methods are interleaved to function correctly, and to allow
evaluate_copyright_placeholdersto emit reproducible results for more-general-case patterns, allow that method to supportSOURCE_DATE_EPOCHinternally.References
Also depends upon a small fixup from #13537 to ensure that the test suite passes reliably when run in entirety.