我刚刚开始学习移植 Android。我遇到了一种新类型的文件，即 .mk 文件。它是 Makefile 的扩展，但我不知道它与 Makefile 有什么不同？那么，有人可以帮助您澄清它们。非常感谢 ！
我刚刚安装了 docker，然后尝试运行hello-world程序。我的服务器在公司代理后面。因此，我根据 docker 手册在名为 的文件中设置了代理环境变量/etc/systemd/system/docker.service.d/http-proxy.conf：
[Service]
Environment="HTTP_PROXY=http://username:password@server:8080"
Environment="HTTPS_PROXY=https://username:password@server:8080"
Environment="NO_PROXY=localhost,127.0.0.1,localaddress,.localdomain.com"
但是，在运行时$ sudo docker run hello-world。我收到错误
Unable to find image 'hello-world:latest' locally
docker: Error response from daemon: Get https://registry-1.docker.io/v2/: proxyconnect tcp: tls: first record does not look like a TLS handshake.
See 'docker run --help'.
这是docker version：
Client: Docker Engine - Community
Version: 19.03.9
API version: 1.40
Go version: go1.13.10
Git commit: 9d988398e7
Built: Fri May 15 00:25:34 2020
OS/Arch: linux/amd64
Experimental: false
Server: …我正在尝试从https://docs.docker.com/compose/gettingstarted/构建 docker 映像示例。我收到了这个错误
Building web
Step 1/9 : FROM python:3.7-alpine
---> e854017db514
Step 2/9 : WORKDIR /code
---> Using cache
---> e15b6e62d8af
Step 3/9 : ENV FLASK_APP app.py
---> Using cache
---> 759c4bc8b254
Step 4/9 : ENV FLASK_RUN_HOST 0.0.0.0
---> Using cache
---> 6d40793f3089
Step 5/9 : RUN apk add --no-cache gcc musl-dev linux-headers
---> Running in 5e40bd670f1b
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz: Permission denied
WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz: Permission denied
ERROR: unsatisfiable constraints:
gcc (missing):
required by: …