Why does docker-compose crash but I can build?

Question

.NET

Here is my

dockerfile

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-bionic AS base
WORKDIR /app
EXPOSE 5002

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS publish
WORKDIR /src
COPY  ./ ./

WORKDIR /src/dirwithService
RUN dotnet publish "Someservice.csproj" -c Debug -o /app/publish

FROM base AS finalGit
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "Someservice.dll"]

:

The build runs without problems.
Docker-compose starts it and several other services. Here is a piece dedicated to it.

version: '3'
services:
    Someservice:
        container_name: Someservice
        build:
            context: dirwithService/Someservice
            dockerfile: Dockerfile
        ports:
        - "5002:80"

It crashes with this text:

Step 8/12 : RUN dotnet publish "Someservice.csproj" -c Debug -o /app/publish                                                                                                                                                   ---> Running in acc9e5d5d7ed                                                                                                                                                                                                          Microsoft (R) Build Engine version 16.7.0-preview-20360-03+188921e2f for .NET                                                                                                                                                          Copyright (C) Microsoft Corporation. All rights reserved.                                                                                                                                                                                                                                                                                                                                                                                                                     MSBUILD : error MSB1009: Project file does not exist.                                                                                                                                                                                  Switch: Someservice.csproj                                                                                                                                                                                                    ERROR: Service 'Someservice' failed to build: The command '/bin/sh -c dotnet publish "Someservice.csproj" -c Debug -o /app/publish' returned a non-zero code: 1

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Seems I understood. This is due to the fact that in the dockerfile I am copying from the parent directory.
It remains to understand how I can pass the required parameter in the docker compos so that the dockerfile can do this.