bazel - 多个 Bazel BUILD 文件出错 : "Target ' bar' is not visible from target 'foo' "

Question

我的项目如下结构:

$ tree
.
├── bar
│   ├── bar.cpp
│   └── BUILD
├── BUILD
├── foo.cpp
└── WORKSPACE

./BUILD 的内容:

cc_binary(
    name = "foo",
    srcs = [ "foo.cpp" ],
    deps = [ "//bar" ],
)

bar/BUILD 的内容:

cc_library(
    name = "bar",
    srcs = ["bar.cpp"],
)

如果我构建 foo ，我会收到以下错误:

Target '//bar:bar' is not visible from target '//:foo'. Check the visibility declaration of the former target if you think the dependency is legitimate.

我需要做什么才能解决依赖关系并成功构建 foo？

Answer 1

从 Bazel docs :

However, by default, build rules are private. This means that they can only be referred to by rules in the same BUILD file. [...] You can make a rule visibile to rules in other BUILD files by adding a visibility = level attribute.

在这种情况下， bar/BUILD 应如下所示:

cc_library(
    name = "bar",
    srcs = ["bar.cpp"],
    visibility = ["//__pkg__"],
)

附加行 visibility = ["//__pkg__"] 允许当前 WORKSPACE 中的所有 BUILD 文件访问目标 bar 。