buildkit/DuplicateStageName

Stage names in a multi-stage build should be unique.

Description

Defining multiple stages with the same name results in an error because the builder is unable to uniquely resolve the stage name reference.

Bad:

FROM debian:latest AS builder
RUN apt-get update; apt-get install -y curl

FROM golang:latest AS builder

Good:

FROM debian:latest AS deb-builder
RUN apt-get update; apt-get install -y curl

FROM golang:latest AS go-builder