Support for bzlmod

[pulanski]

With bzlmod (https://bazel.build/build/bzlmod) soon to become generally available in Bazel version 6.0 in Q4 (https://bazel.build/about/roadmap), I was wondering if there was any plan for adding bzlmod support for copybara via the BCR (https://registry.bazel.build/).

[keith]

#287

[dmivankov]

copybara is in bzlmod now https://registry.bazel.build/modules/copybara but it doesn't work because of clashes with @maven targets

$ bazel run @copybara//java/com/google/copybara:copybara
...
ERROR: ... external/copybara+/third_party/BUILD:77:13: no such target '@@rules_jvm_external++maven+maven//:org_jcommander_jcommander': target 'org_jcommander_jcommander'

and with following patch

diff --git third_party/BUILD third_party/BUILD
index aa6b0cb2..18984412 100644
--- third_party/BUILD
+++ third_party/BUILD
@@ -77,7 +77,7 @@ java_library(
 java_library(
     name = "jcommander",
     exports = [
-        "@maven//:org_jcommander_jcommander",
+        "@copybara_maven//:org_jcommander_jcommander",
     ],
 )

it still fails, now with

... external/copybara++non_module_deps+io_bazel/third_party/BUILD:348:6: no such target '@@rules_jvm_external++maven+maven//:com_github_stephenc_jcip_jcip_annotations': target 'com_github_stephenc_jcip_jcip_annotations' not declared in package ''

which looks harder to fix, probably comes from

def _non_module_deps(_):
    # LICENSE: The Apache Software License, Version 2.0
    maybe(
        http_archive,
        name = "io_bazel",
        sha256 = bazel_sha256,
        strip_prefix = "bazel-" + bazel_version,
        url = "https://github.com/bazelbuild/bazel/archive/" + bazel_version + ".zip",
    )