tally/circular-stage-deps¶

Detects circular dependencies between build stages.

Property	Value
Severity	Error
Category	Correctness
Default	Enabled

Description¶

Detects cycles in the stage dependency graph. A cycle occurs when stages form mutual dependencies through COPY --from=<stage>, RUN --mount from=<stage>, or FROM <stage> references.

Circular dependencies always cause build failures because no stage in the cycle can finish building before the others — each waits for output from another.

Common causes:

A refactoring accidentally swaps stage references
An AI-generated patch links stages in both directions
A copy-paste introduces a forward COPY --from that mirrors an existing backward reference

Examples¶

Bad¶

# builder copies from runtime, runtime copies from builder → cycle
FROM golang:1.22-alpine AS builder
COPY --from=runtime /usr/local/bin/tini /usr/local/bin/tini
RUN go build -o /app ./cmd/server

FROM alpine:3.19 AS runtime
COPY --from=builder /app /usr/local/bin/app
RUN apk add --no-cache ca-certificates

FROM runtime
ENTRYPOINT ["/usr/local/bin/app"]

Good¶

# Dependencies flow in one direction: deps → builder → runtime
FROM golang:1.22-alpine AS builder
RUN go build -o /app ./cmd/server

FROM alpine:3.19 AS runtime
RUN apk add --no-cache ca-certificates
COPY --from=builder /app /usr/local/bin/app

FROM runtime
ENTRYPOINT ["/usr/local/bin/app"]

Configuration¶

[rules.tally.circular-stage-deps]
severity = "error"  # Options: "off", "error", "warning", "info", "style"