René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"determinism: the stream-lost-after-note, completed history recorded different traces once (commit 9d71756)","articleBody":"**Tags:** determinism, oracle-gaps, #57 (`feat/gap-cli-stream-log`).\n\n**Commit:** `9d71756` (pool run `r57m-det`, two runs of one history, the same unit as `determinism: constructed history: a stream log lost after its note, then completed`). Run once; the same unit passed at `7a59640` and `92d7ab0`.\n\n**Observed:** the two runs of the history recorded different `unwritableLog` traces. The first 2,000 characters of each are identical (the difference is later, which #81 hides):\n\nFirst run (the 2,000-character prefix, 1986 characters):\n```\nunwritableLog {\"ending\":\"complete\",\"exit\":0,\"signal\":null,\"stdout\":\"oracle-gaps: note log \u003cout>/stream.log\\noracle-gaps: baseline pass tests/a.test.ts: 1 test\\noracle-gaps: baseline pass tests/b.test.ts: 0 tests, 1 skipped\\noracle-gaps: baseline pass tests/c.test.ts (ordinary): 0 tests, 1 skipped\\noracle-gaps: baseline all 2 oracle files pass\\noracle-gaps: summary 395076321439: 44 mutants, 1 killed, 18 gaps, 11 unowned (warnings). 11 source files, 2 oracle files, 1 ordinary test files, 0 authored mutants, seed 1, pool threads.\\noracle-gaps: legend unreached: Add an owner test that runs line N and asserts on its result.\\noracle-gaps: function fn e0 (..gen/extra.ts)\\noracle-gaps: gap unreached L2 ..gen/extra.ts:M1 ` out.push('s19'); ` → ` ; `\\noracle-gaps: function fn help (src/es-function.ts)\\noracle-gaps: gap unreached L2 es-function.ts:M1 ` out.push('s3'); ` → ` ; `\\noracle-gaps: function fn default (src/es-function.ts)\\noracle-gaps: gap unreached L5 es-function.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/es-arrow.ts)\\noracle-gaps: gap unreached L2 es-arrow.ts:M1 ` out.push('s5'); ` → ` ; `\\noracle-gaps: function fn default (src/es-arrow.ts)\\noracle-gaps: gap unreached L5 es-arrow.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/es-paren.ts)\\noracle-gaps: gap unreached L2 es-paren.ts:M1 ` out.push('s7'); ` → ` ; `\\noracle-gaps: function fn default (src/es-paren.ts)\\noracle-gaps: gap unreached L5 es-paren.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/cjs.js)\\noracle-gaps: gap unreached L2 cjs.js:M1 ` out.push('s9'); ` → ` ; `\\noracle-gaps: function fn default (src/cjs.js)\\noracle-gaps: gap unreached L5 cjs.js:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/cjs-chained.js)\\noracle-gaps: gap unreached L2 cjs-chained.js:M1 ` out.push('s11'); ` → ` ; `\\noracle-gaps: function fn default (src/cjs-chained.js)\\noracle-gaps: gap unreached L5 cjs-chained.js:M2 ` help(out); ` → ` ; `\\noracle-gaps: function f\n```\n\nSecond run (prefix, 1986 characters, identical up to the truncation):\n```\nunwritableLog {\"ending\":\"complete\",\"exit\":0,\"signal\":null,\"stdout\":\"oracle-gaps: note log \u003cout>/stream.log\\noracle-gaps: baseline pass tests/a.test.ts: 1 test\\noracle-gaps: baseline pass tests/b.test.ts: 0 tests, 1 skipped\\noracle-gaps: baseline pass tests/c.test.ts (ordinary): 0 tests, 1 skipped\\noracle-gaps: baseline all 2 oracle files pass\\noracle-gaps: summary 395076321439: 44 mutants, 1 killed, 18 gaps, 11 unowned (warnings). 11 source files, 2 oracle files, 1 ordinary test files, 0 authored mutants, seed 1, pool threads.\\noracle-gaps: legend unreached: Add an owner test that runs line N and asserts on its result.\\noracle-gaps: function fn e0 (..gen/extra.ts)\\noracle-gaps: gap unreached L2 ..gen/extra.ts:M1 ` out.push('s19'); ` → ` ; `\\noracle-gaps: function fn help (src/es-function.ts)\\noracle-gaps: gap unreached L2 es-function.ts:M1 ` out.push('s3'); ` → ` ; `\\noracle-gaps: function fn default (src/es-function.ts)\\noracle-gaps: gap unreached L5 es-function.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/es-arrow.ts)\\noracle-gaps: gap unreached L2 es-arrow.ts:M1 ` out.push('s5'); ` → ` ; `\\noracle-gaps: function fn default (src/es-arrow.ts)\\noracle-gaps: gap unreached L5 es-arrow.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/es-paren.ts)\\noracle-gaps: gap unreached L2 es-paren.ts:M1 ` out.push('s7'); ` → ` ; `\\noracle-gaps: function fn default (src/es-paren.ts)\\noracle-gaps: gap unreached L5 es-paren.ts:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/cjs.js)\\noracle-gaps: gap unreached L2 cjs.js:M1 ` out.push('s9'); ` → ` ; `\\noracle-gaps: function fn default (src/cjs.js)\\noracle-gaps: gap unreached L5 cjs.js:M2 ` help(out); ` → ` ; `\\noracle-gaps: function fn help (src/cjs-chained.js)\\noracle-gaps: gap unreached L2 cjs-chained.js:M1 ` out.push('s11'); ` → ` ; `\\noracle-gaps: function fn default (src/cjs-chained.js)\\noracle-gaps: gap unreached L5 cjs-chained.js:M2 ` help(out); ` → ` ; `\\noracle-gaps: function f\n```\n\n**Suspected cause:** wall-clock timing in the CLI's output (#84's class). The difference cannot be seen until #81 is fixed. The full traces of a passing/failing pair would settle it; the run's log is not kept.\n\n**Links:** #81 (the 2,000-character truncation that hides the difference), #84 (wall-clock heartbeats, a suspected cause).\n\n**Not blocking:** this was one observed flake; the unit passed in two later runs. Filed under P4 (an observed counterexample is filed, not kept as a watch item).\n","author":{"url":"https://github.com/KyleAMathews","@type":"Person","name":"KyleAMathews"},"datePublished":"2026-11-15T06:15:34Z","url":"https://github.com/TanStack/oracles/issues/100"}