从父目录进行相对导入

这给出了一个模棱两可的错误：

本地是指文件系统相对路径。显然，以..开头的相对路径是本地的，所以诀窍就是获取 go 命令将main作为本地包对待。当你键入 go build 时显然没有这样做，但是当你输入 go build main.go 的时候不会这样做。

How does one do a relative import from a parent directory?

From meme/cmd/meme:

This gives an ambiguous error:

How do I import locally from a parent directory?

Thanks for adding to your question. First, an answer, then some explanation. I built your code by,

I was wrong in my comment earlier when I said go install works; I should have said go build.

The key however is that go build alone does not work; you must type go build main.go. This is because the go command does not allow "local imports in non-local packages." You are right that spec is of little help here. It weasels out saying, "The interpretation of the ImportPath is implementation-dependent." The current implementation behavior was set with CL 5787055, which was subsequently debated at length on Go-nuts.

"Local" means indicated with a file system relative path. Obviously a relative path starting with .. is local, so the trick is just getting the go command to treat main as a local package as well. It apparently doesn't do this when you type go build, but does when you type go build main.go.