Turbopack: Document the reasons for the current design of parse_segment_config_from_source

[bgw]

Document all my learnings from my saga of trying to get Flow syntax to work in entrypoints with the babel loader and ultimately giving up, so that hopefully others don't waste their time like I did.

https://vercel.slack.com/archives/C03EWR7LGEN/p1757982766169869

Closes PACK-5488

[bgw]

• Turbopack: Document the reasons for the current design of parse_segment_config_from_source #83919 👈 (View in Graphite)
• canary

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[ijjk]

Tests Passed

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #83919 will not alter performance

_{Comparing bgw/document-segment-config-implementation (f5f7f1b) with canary (f272121)}

Summary

✅ 9 untouched
⏩ 3 skipped¹

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[bgw]

Merge activity

• Sep 18, 9:28 AM UTC: @bgw merged this pull request with Graphite.