如何通过Bazel模块扩展引入非Bazel的GitHub仓库依赖

问题背景 #

尝试通过Bazel模块扩展将非Bazel项目的GitHub仓库（whisper.cpp v1.4.0）加入构建，使用git_repository拉取仓库后，构建时提示找不到外部仓库的BUILD文件。

当前配置文件：

MODULE.bazel #

## MODULE.bazel
module(
    name = "test",
)

non_module_dependencies = use_extension("//:deps.bzl", "data_deps_ext")
use_repo(non_module_dependencies, "whisper")

deps.bzl #

load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")

def whisper():
    git_repository(
        name = "whisper",
        remote = "https://github.com/ggerganov/whisper.cpp.git",
        tag = "v1.4.0"
    )

def _data_deps_extension_impl(_):
    whisper()

data_deps_ext = module_extension(
    implementation = _data_deps_extension_impl,
)

BUILD #

cc_binary(
    name = "main",
    srcs = ["main.cc"],
    deps = [
        "@whisper"
    ]
)

错误信息 #

DEBUG: Repository _main~data_deps_ext~whisper instantiated at:
  callstack not available
Repository rule git_repository defined at:
  /private/var/tmp/_bazel_victor/1cabe6594cc48c856544c639052f58cd/external/bazel_tools/tools/build_defs/repo/git.bzl:181:33: in <toplevel>
ERROR: /Users/victor/Desktop/Check/cpp/main/BUILD:1:10: no such package '@_main~data_deps_ext~whisper//': BUILD file not found in directory '' of external repository @_main~data_deps_ext~whisper. Add a BUILD file to a directory to mark it as a package. and referenced by '//main:main'
ERROR: Analysis of target '//main:main' failed; build aborted: Analysis failed
INFO: Elapsed time: 5.239s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (52 packages loaded, 211 targets configured)
    Fetching repository @bazel_tools~cc_configure_extension~local_config_cc; Running xcode-locatorlysis of target '//main:main' failed; build aborted: Analysis failed
INFO: Elapsed time: 5.239s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (52 packages loaded, 211 targets configured)
    Fetching repository @bazel_tools~cc_configure_extension~local_config_cc; Running xcode-locator

错误原因 #

git_repository仅负责拉取仓库，但whisper.cpp本身不是Bazel项目，根目录没有BUILD文件，Bazel无法识别该仓库的包结构和目标。需要使用支持注入自定义BUILD文件的仓库规则，为非Bazel项目补充Bazel构建规则。

解决方案 #

修改deps.bzl，使用new_git_repository替代git_repository，并注入自定义BUILD规则，让Bazel能识别whisper.cpp的源文件和头文件。

步骤1：更新deps.bzl #

load("@bazel_tools//tools/build_defs/repo:git.bzl", "new_git_repository")

def whisper():
    new_git_repository(
        name = "whisper",
        remote = "https://github.com/ggerganov/whisper.cpp.git",
        tag = "v1.4.0",
        build_file_content = """
cc_library(
    name = "whisper",
    srcs = glob(["*.c", "*.cpp"]),
    hdrs = glob(["*.h", "*.hpp"]),
    includes = ["."],
    visibility = ["//visibility:public"],
)
""",
    )

def _data_deps_extension_impl(_):
    whisper()

data_deps_ext = module_extension(
    implementation = _data_deps_extension_impl,
)

• new_git_repository的build_file_content字段直接注入自定义BUILD文件，定义了一个cc_library目标，包含仓库中所有C/C++源文件和头文件。
• includes = ["."]确保编译时可以直接引用根目录的whisper.h等头文件。
• visibility = ["//visibility:public"]允许主项目引用这个库。

步骤2：调整主BUILD文件的依赖 #

依赖需要指向自定义的cc_library目标，而非仓库本身：

cc_binary(
    name = "main",
    srcs = ["main.cc"],
    deps = [
        "@whisper//:whisper"
    ]
)

步骤3：验证构建 #

执行bazel build //main:main，Bazel会拉取whisper.cpp仓库，使用注入的BUILD文件构建库，再编译你的main.cc。

内容的提问来源于stack exchange，提问作者Victor M