fetch
ERROR: IO ERROR
WARNING: Ignoring APKINDEX.104533ab.tar.gz: No such file or directory
ERROR: unsatisfiable constraints:
go (missing):
required by: world[go]
git (missing):
required by: world[git]
mercurial (missing):
required by: world[mercurial]
Service 'logspout' failed to build: The command '/bin/sh -c cd /src && ./build.sh "$(cat VERSION)-custom"' returned a non-zero code: 3
通常你会直接用浏览器或者 curl 来试前面访问错误的 URL，却发现能正常访问。然后你就郁闷了，因为上述错误发生在 docker build 过程中，还不好调试。
VBoxManage modifyvm <vm-name> --natdnsproxy1 off --natdnshostresolver1 off