A workflow run dispatched two @make agents in parallel. Both agents
write source files, run cargo verification commands, and may both
target the same file (e.g. src/lib.rs for a new `pub mod` plus a
later registration) — concurrent edits corrupt each other and Cargo's
target/ lock serialises the builds anyway, so parallelism only adds
risk without giving speedup.
Phase 7 now states explicitly that @make dispatches are SEQUENTIAL —
never in parallel — and lists the reasons inline. The rule covers
all @make invocations: standard mode, TDD mode, the Rust stub-pass
and body-pass, and integration-fix dispatches. Stub-pass/body-pass
ordering within a task is strict so @test always RED-verifies against
a deterministic crate state.
Phase 6's parallelism rule splits per language: Python parallel
@test is still allowed for disjoint test files, but Rust @test runs
sequentially since cargo serialises the build and shared crate-level
helper files race.
Harald Hoyer
91e8aab383