heap-repro

Overview ¶

heap-repro drives one long-lived Dagger session through many module function calls while sampling the engine's heap profile, then renders the samples as a stacked area chart so the memory retained per nested client can be compared between engine builds.

Every call spawns a fresh module runtime, which connects back to the engine as a nested client with its own telemetry. Before client reclamation those runtimes stayed alive until the session ended, so the heap grew with every call; after it, the heap stays flat.

Usage, from a checkout whose dev engine is running (see hack/dev):

./hack/with-dev go run ./hack/heap-repro record -label main -out main.json
./hack/with-dev go run ./hack/heap-repro record -label branch -out branch.json
go run ./hack/heap-repro chart -out heap.html main.json branch.json

hack/heap-repro/run.sh wraps the engine rebuild and the record step for one worktree.