fix(setuptools): use guess-next-dev schema

[tabgok]

A backport (#8367) changed our setuptools_scm schema from guess-next-dev to release-branch-semver for the 2.5 and 2.6 releases; but this change was never put into mainline. This change fixes the issue.

Prior to this change, setuptools_scm reported the version for patch releases as the next minor release. Afterwards, versions are patch releases (as expected).

Checklist

• Change(s) are motivated and described in the PR description
• Testing strategy is described if automated tests are not included in the PR
• Risks are described (performance impact, potential for breakage, maintainability)
• Change is maintainable (easy to change, telemetry, documentation)
• Library release note guidelines are followed or label changelog/no-changelog is set
• Documentation is included (in-code, generated user docs, public corp docs)
• Backport labels are set (if applicable)
• If this PR changes the public interface, I've notified @DataDog/apm-tees.
• If change touches code that signs or publishes builds or packages, or handles credentials of any kind, I've requested a review from @DataDog/security-design-and-guidance.

Reviewer Checklist

• Title is accurate
• All changes are related to the pull request's stated goal
• Description motivates each change
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Change is maintainable (easy to change, telemetry, documentation)
• Release note makes sense to a user of the library
• Author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: teague.bick/DSMS-16/fix-schema
Commit report: 32ffb60
Test service: dd-trace-py

✅ 0 Failed, 171692 Passed, 1071 Skipped, 11h 26m 11.03s Total duration (21m 58.36s time saved)

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-03-27 22:20:26

Comparing candidate commit 32ffb60 in PR branch teague.bick/DSMS-16/fix-schema with baseline commit be880c1 in branch main.

Found 5 performance improvements and 3 performance regressions! Performance is the same for 193 metrics, 9 unstable metrics.

scenario:flasksimple-appsec-telemetry

• 🟥 execution_time [+220.949µs; +263.140µs] or [+3.527%; +4.201%]

scenario:flasksimple-tracer

• 🟥 execution_time [+223.746µs; +270.052µs] or [+3.568%; +4.306%]

scenario:httppropagationextract-large_header_no_matches

• 🟩 max_rss_usage [-744.847KB; -668.273KB] or [-3.406%; -3.056%]

scenario:httppropagationextract-medium_header_no_matches

• 🟩 max_rss_usage [-761.444KB; -672.566KB] or [-3.482%; -3.076%]

scenario:httppropagationextract-none_propagation_style

• 🟩 max_rss_usage [-908.887KB; -496.451KB] or [-4.152%; -2.268%]

scenario:httppropagationextract-wsgi_invalid_priority_header

• 🟥 max_rss_usage [+435.174KB; +703.514KB] or [+2.057%; +3.325%]

scenario:httppropagationextract-wsgi_large_header_no_matches

• 🟩 max_rss_usage [-808.458KB; -722.626KB] or [-3.691%; -3.299%]

scenario:httppropagationextract-wsgi_medium_header_no_matches

• 🟩 max_rss_usage [-790.987KB; -715.931KB] or [-3.615%; -3.272%]

[P403n1x87]

Let's add a comment above this property explaining why this needs to be release-branch-semver on the main branch

[christophe-papazian]

I am requesting this PR to be closed.

Explanations:

we have 2 possible policies for setup tools, none of them is ok for all cases.
Setuptools is looking back from current commit and looking for the first version tag in ancestor commit.
Then either it’s using that version with release-branch-semver or using the next minor dev version with guess-next-dev

Currently we need the next minor dev version to be able to enable new system tests for new “just merged in main” features. But we need the same version policy for all backports, otherwise we will enable tests in system tests for features merged in the next version.

So for now, we are using “guess-next-dev” in main and as soon as it’s needed we change it into “release-branch-semver” for minor version branches for all backports.

(This is a known problem that I already explained to a guild meeting, while sponsoring for one of the following solution, but this was never supported by the guild)

What are doing other big python projects on that problem ?

• Do as we are doing (not really satisfying)
• Use always “release-branch-semver” but add a new minor dev tag (for next unreleased minor version, like 4.15.0.dev) to the main branch on an empty commit after each creation of a new minor/major branch (like v4.14). We would need to integrate that step to our release todo list
• Drop setuptools for version computation and have the version as constants in a file that would need to be updated for each release. Require more work but with less dependency, simpler build process and more control.

[tabgok]

I created an issue here: #8801
And a specific PR for 2.7 here: #8800
And an explanatory comment here: #8802