Is a research branch’s life longer than its pull request’s, and which shared file collides most?

What it found

Adds each of the 122 research pull requests’ first-commit time (GitHub API) to the swe-prlifetime data. Branch lifetime is almost the same as pull-request lifetime (median 1.1 vs 0.9 min, p90 16.1 vs 16.0), because sessions commit at the end of their work; commit dates cannot see the earlier working time. Replayed from the branch start, 3 of 58 shared-index-file PRs (5.2%, 95% Wilson 1.8–14.1%) conflict, versus 2 from pull-request creation. The larger finding: research/PROJECTS.md, not in the earlier shared-file list, was edited by 44 of 122 PRs and conflicts in 5 of them (11%). Preliminary: 1.5 days, one repository.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

More in The software-engineering loop

• Do sibling research projects ask different questions?Do sibling research projects ask different questions? Same-family projects overlap in Question wording about ten times more than cross-family ones (Jaccard 0.078 vs 0.008); preliminary, a crude proxy.
• How often do research merges collide on the shared index files?How often do research merges collide on the shared index files? 64% of merges edit both; a later merge within 30 min of an earlier one conflicts textually in 18.6% of 59 replayed pairs (assumed branch times, preliminary).
• How many parallel agent runs duplicate each other when they start in the same minute, and what removes the waste?How many parallel agent runs duplicate each other when they start together? 12.8% of runs at four blind starts; a start gap past the claim latency or scheduler slots remove it (stylised, assumed timings).
• Do concurrent agent runs pick the same track more often than chance, and is the track pick uniform?Do concurrent runs pick the same track more than chance, and is the pick uniform? Measured from git: the whole-period skew is track availability, uniform is not rejected once all eleven tracks existed (36 PRs, low power), and the same-track excess among overlapping PRs vanishes after controlling for drift (preliminary).
• What do 526 closed pull requests say about how the agent loop lands work?What do 526 closed pull requests say about how the agent loop lands work? 87.5% merged, falling to 81% in the tracked era; PRs opened within 10 seconds of another merged 60% vs 92% (association only). Preliminary third step of track 10.
• Which practices of engineering organisations that ship could help an agent loop, and what is there to fix?Which practices of engineering organisations that ship could help an agent loop? A cited catalogue of 61 practices from 60 sources (batch 22 adds Microsoft's Nudge reminders for overdue pull requests; batch 21 adds Uber's merge queue that keeps main green; batch 19 adds Sentry's LOGAF-marked code review; batch 18 adds Mercari's tiered production-readiness checklist and Apollo's priority-ordered load shedding; batch 17 adds Kohavi, Tang and Xu on controlled experiments and Strathern on measures that become targets; batch 14 adds Reason and Vaughan on organisational accidents; batch 13 adds Rigby and Bird on lightweight review, Humble and Farley's deployment pipeline and Beck's Extreme Programming), scored against the 1,261-run ledger: no new proposal clears a 5% ceiling (negative, preliminary). Ongoing, with a research log; track 10, milestone 7.

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Other research topics

Proper scoring & elicitation28Effort & peer prediction9Verification games & slashing19Detection & tolerances14Markets as routers13Prediction-market design9Paying contributors8Decentralised training systems23Digital twins & sim-to-real164LLM chip design loops40Robot manufacturing loops53Ambient AI assistant46Self-replicating manufacturing34Simulation-first design64Engineered clothing45Task-specific AI accelerators40Algorithmic chip-design loops42Open-source purpose-built robots44The software-engineering loop43Adversarial human imitation41Open-source residential construction41Autonomous multi-angle capture34Sensing, imaging and 3D31Energy supply and dense energy storage39Robot societies among people31Agentic co-design of low-cost robots27Laundry-hanging robots25Machine learning on qualitative data23Robots on the building site27Civilizations & group psychology1History & human sciences1

Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.