码头组成卷不能挂载目录到一个文件（反之亦然）

我正在使用以下docker-compose配置块的容器：

frontend: image: zzrot/alpine-caddy ports: - "433:433" - "80:80" volumes: - ./share/etc/Caddyfile:/etc/Caddyfile - ./root/static:/var/www/htm 

当我运行docker-compose时，我看到以下错误：

 ERROR: oci runtime error: container_linux.go:262: starting container process caused "process_linux.go:339: container init caused \"rootfs_linux.go:57: mounting \\\"/Users/adam/code/projects/BicycleEvents-Web/share/etc/Caddyfile\\\" to rootfs \\\"/var/lib/docker/aufs/mnt/9e45393ec987dcca75752736c2b4af323ce78838b4d9233059e4d24c6ada193a\\\" at \\\"/var/lib/docker/aufs/mnt/9e45393ec987dcca75752736c2b4af323ce78838b4d9233059e4d24c6ada193a/etc/Caddyfile\\\" caused \\\"not a directory\\\"\"" : Are you trying to mount a directory onto a file (or vice-versa)? Check if the specified host path exists and is the expected type 

这是前一阵子工作，但我最近升级码头机，并试图重建容器。

码头机版本： docker-machine version 0.12.1, build c8b17e8

码头合成版本：

 1.6.0, build d99cad6 docker-py version: 1.7.0 CPython version: 2.7.11 OpenSSL version: OpenSSL 0.9.8zh 14 Jan 2016 

码头版本：

 Client: Version: 1.10.1 API version: 1.22 Go version: go1.5.3 Git commit: 9e83765 Built: Thu Feb 11 19:14:21 2016 OS/Arch: darwin/amd64 Server: Version: 17.06.0-ce API version: 1.30 Go version: go1.8.3 Git commit: 02c1d87 Built: Fri Jun 23 21:19:04 2017 OS/Arch: linux/amd64