Why. Dynamic typing's structural weakness is that errors surface at runtime. Deterministic replay converts that into a capability no incumbent ships: every failure arrives as a byte-identical reproducer. EigenOS's flight recorder (crash → journal_replay of "lastboot") already proved the pattern; bring it to every script and package author.
What.
eigenscript --test --trace-on-fail: record a tape per test; on failure, print the exact EIGS_REPLAY=... eigenscript ... invocation alongside the error + stack trace.- A CI leg running the suite this way, archiving tapes of any red test as workflow artifacts.
docs/TRACE.md "Every failure is a tape" section documenting the canonical loop: failure → replay → prev of / state_at interrogation.
Caveat. Archived tapes are same-binary artifacts until the tape-format versioning decision lands (see the tape-versioning design issue); document that explicitly.
Acceptance. A deliberately failing test prints a replay invocation that reproduces the failure byte-for-byte; CI artifact contains the tape.
Effort: days. Source: 2026-07-04 survey (correctness dimension; critic top-5).
Why. Dynamic typing's structural weakness is that errors surface at runtime. Deterministic replay converts that into a capability no incumbent ships: every failure arrives as a byte-identical reproducer. EigenOS's flight recorder (crash →
journal_replay of "lastboot") already proved the pattern; bring it to every script and package author.What.
eigenscript --test --trace-on-fail: record a tape per test; on failure, print the exactEIGS_REPLAY=... eigenscript ...invocation alongside the error + stack trace.docs/TRACE.md"Every failure is a tape" section documenting the canonical loop: failure → replay →prev of/state_atinterrogation.Caveat. Archived tapes are same-binary artifacts until the tape-format versioning decision lands (see the tape-versioning design issue); document that explicitly.
Acceptance. A deliberately failing test prints a replay invocation that reproduces the failure byte-for-byte; CI artifact contains the tape.
Effort: days. Source: 2026-07-04 survey (correctness dimension; critic top-5).