Docker无法从Alpine上build立apk安装

在完成构build包之后，我尝试删除构build过程中所需的开销包，但出现以下错误：

ERROR: Service 'app' failed to build: The command '/bin/sh -c apk --update add --virtual build-deps gcc python-dev musl-dev build-base git postgresql-dev && pip install -r requirements.txt && pip install --upgrade -t /usr/local/lib/python3.6/site-packages git+git://github.com/mlmarius/momoko.git@master#egg=momoko && apk del binutils-libs binutils gcc g++ build-base gmp isl libgcc libstdc++ python2 python2-dev libgomp libatomic pkgconf python-dev mysl-dev build-base git postgresql-dev && rm -rf /var/cache/apk/*' returned a non-zero code: 1 

这是我的Dockerfile：

 FROM python:3.6.3-alpine3.6 ADD ./app /app WORKDIR /app RUN apk --update add \ --virtual build-deps gcc python-dev musl-dev \ build-base git \ postgresql-dev \ && pip install -r requirements.txt \ && pip install --upgrade -t /usr/local/lib/python3.6/site-packages git+git://github.com/mlmarius/momoko.git@master#egg=momoko \ && apk del \ binutils-libs binutils gcc g++ build-base \ gmp isl libgcc libstdc++ python2 python2-dev \ libgomp libatomic pkgconf python-dev mysl-dev \ build-base git postgresql-dev \ && rm -rf /var/cache/apk/* ENTRYPOINT ["python", "main.py"] 

如果我删除apk del和rm -rf命令，那么构build成功。 有没有人有任何ideea为什么我的apk del失败的构build？

PS：如果我login到未完成的容器并手动运行del命令，那么我得到以下警告：

 WARNING: Ignoring APKINDEX.84815163.tar.gz: No such file or directory WARNING: Ignoring APKINDEX.24d64ab1.tar.gz: No such file or directory