项目具有内部依赖项时，bazel golang构建失败

Question

I'm on MacOS 10.13.2. Go 1.10. bazel 0.11.1

I need to compile a repo that has 2 projects (project1 and project2). project1 has 2 subpacakges. p1lib and dep1 p1lib uses dep1.

I generate BUILD files with gazelle, files look ok.

gazelle -go_prefix=github.com/BazelBuildForGo

But when I run build I get an error that says that I'm missing direct dependency.

bazel build //project1
INFO: Analysed target //project1:project1 (3 packages loaded).
INFO: Found 1 target...
ERROR: /private/var/tmp/_bazel_user1/df78026a5ee0c7ed3d23dd05c3a3b1f7/external/com_github_wix_private_bazelbuildforgo/project1/p1lib/BUILD.bazel:3:1: GoCompile external/com_github_wix_private_bazelbuildforgo/project1/p1lib/darwin_amd64_stripped/go_default_library~/github.com/BazelBuildForGo/project1/p1lib.a failed (Exit 1)
2018/03/25 18:02:55 missing strict dependencies:
    external/com_github_wix_private_bazelbuildforgo/project1/p1lib/p1lib.go: import of github.com/wix-private/BazelBuildForGo/project1/dep1, which is not a direct dependency
Target //project1:project1 failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 0.358s, Critical Path: 0.12s
FAILED: Build did NOT complete successfully

My project can be found here https://github.com/wix-playground/BazelBuildForGo

Answer 1

I think the problem is that the import prefix you passed to Gazelle on the command line (github.com/BazelBuildForGo) is different from the imports in the .go files (github.com/wix-private/BazelBuildForGo). When Gazelle sees imports that are outside the current prefix, it will generate external dependencies for those imports, and those dependencies will be missing:

go_library(
    name = "go_default_library",
    srcs = ["p1lib.go"],
    importpath = "github.com/BazelBuildForGo/project1/p1lib",
    visibility = ["//visibility:public"],
    deps = ["@com_github_wix_private_bazelbuildforgo//project1/dep1:go_default_library"],
)

The fix for this is pretty easy though. Just run Gazelle with the prefix github.com/wix-private/BazelBuildForGo. You actually already have this in //:gazelle, so just run that, then rebuild.

$ bazel run //:gazelle
$ bazel build //...

That will change the go_library rule above to this:

go_library(
    name = "go_default_library",
    srcs = ["p1lib.go"],
    importpath = "github.com/wix-private/BazelBuildForGo/project1/p1lib",
    visibility = ["//visibility:public"],
    deps = ["//project1/dep1:go_default_library"],
)