GoLand调试器不会在Docker容器中调试go代码时在源代码中停止

I am using:

Mac os High sierra 10.13.6
Docker Community Edition 18.06.1-ce
GoLand 2018.2.3
Go 1.11.1 (installed by brew at /usr/local/Cellar/go/1.11.1/libexec

I am following the instructions at https://blog.jetbrains.com/go/2018/04/30/debugging-containerized-go-applications/ to remotely debug go code running in a docker container from GoLand IDE.

However, the debugger doesn't stop at the source code on calling http://localhost:8080

If I use Dockerfile.1, I see this error on running the container:

Could not create config directory: user: Current not implemented on linux/amd64.

If I use Dockerfile.2, I don't see any error on running the container.

However, debugger doesn't stop at any breakpoints in the source.

---- Dockerfile.1 ----

FROM golang:1.10.1-alpine3.7 AS build-env
ENV CGO_ENABLED 0
ADD . /go/src/hello

RUN go build -gcflags "all=-N -l" -o /server hello

RUN apk add --no-cache git
RUN go get github.com/derekparker/delve/cmd/dlv

FROM alpine:3.7

EXPOSE 8080 40000

RUN apk add --no-cache libc6-compat

WORKDIR /

COPY --from=build-env /server /
COPY --from=build-env /go/bin/dlv /

CMD ["/dlv", "--listen=:40000", "--headless=true", "--api-version=2", "exec", "/server"]

---- Dockerfile.2 ----

FROM golang:1.10.1-alpine3.7 AS build-env
ADD . /go/src/hello

RUN apk add --no-cache libc6-compat build-base

RUN go build -gcflags "all=-N -l" -o /server hello

RUN apk add --no-cache git
RUN go get github.com/derekparker/delve/cmd/dlv

FROM alpine:3.7

EXPOSE 8080 40000

RUN apk add --no-cache libc6-compat

WORKDIR /

COPY --from=build-env /server /
COPY --from=build-env /go/bin/dlv /

CMD ["/dlv", "--listen=:40000", "--headless=true", "--api-version=2", "exec", "/server"]