POC - go.mod replace with ModulePath

internal/bzlmod/go_deps.bzl

@@ -473,6 +473,7 @@ def _go_deps_impl(module_ctx):
                 version = new_version,
                 raw_version = replace.version,
             )
+
             if path in root_versions:
                 if replace != replace.to_path:
                     # If the root module replaces a Go module with a completely different one, do
@@ -522,7 +523,6 @@ def _go_deps_impl(module_ctx):
             # Do not create a go_repository for a dep shared with the non-isolated instance of
             # go_deps.
             continue
-
         go_repository_args = {
             "name": module.repo_name,
             "importpath": path,
@@ -549,6 +549,13 @@ def _go_deps_impl(module_ctx):
                 "version": "v" + module.raw_version,
             })
 
+        # TODO: remove the need for a sentinel value, make it explicit instead
+        if module.raw_version == "999.999.999":
+            go_repository_args.update({
+                "version": None,
+                "path": module.replace,
+            })
+
         go_repository(**go_repository_args)
 
     # Create a synthetic WORKSPACE file that lists all Go repositories created
@@ -593,8 +600,11 @@ def _get_sum_from_module(path, module, sums):
         entry = (module.replace, module.raw_version)
 
     if entry not in sums:
-        # TODO: if no sum exist, this is probably because a go mod tidy was missed
-        fail("No sum for {}@{} found".format(path, module.raw_version))
+        if module.raw_version == "999.999.999":
+            return ""
+        else:
+            # TODO: if no sum exist, this is probably because a go mod tidy was missed
+            fail("No sum for {}@{} found".format(path, module.raw_version))
 
     return sums[entry]
 

internal/bzlmod/go_mod.bzl

@@ -252,10 +252,11 @@ def _parse_replace_directive(state, tokens, path, line_no):
             version = _canonicalize_raw_version(tokens[4]),
         )
     else:
-        fail(
-            "{}:{}: replace directive must follow pattern: ".format(path, line_no) +
-            "'replace from_path from_version => to_path to_version' or " +
-            "'replace from_path => to_path to_version'",
+        state["replace"][from_path] = struct(
+            from_version = None,
+            to_path = tokens[2],
+            # TODO: should version be None here? or some sentinel Null value version?
+            version = _canonicalize_raw_version("999.999.999"),
         )
 
 def _tokenize_line(line, path, line_no):

internal/go_repository.bzl

@@ -181,6 +181,8 @@ def _go_repository_impl(ctx):
             "-version=" + ctx.attr.version,
             "-sum=" + ctx.attr.sum,
         ]
+    elif ctx.attr.path:
+        pass
     else:
         fail("one of urls, commit, tag, or importpath must be specified")
 
@@ -237,6 +239,77 @@ def _go_repository_impl(ctx):
 
     env.update({k: ctx.os.environ[k] for k in env_keys if k in ctx.os.environ})
 
+    if ctx.attr.path:
+        local_path_env = dict(env)
+        local_path_env["GOSUMDB"] = "off"
+
+        # Override external GO111MODULE, because it is needed by module mode, no-op in repository mode
+        local_path_env["GO111MODULE"] = "on"
+
+        if hasattr(ctx, "watch_tree"):
+            # https://github.com/bazelbuild/bazel/commit/fffa0affebbacf1961a97ef7cd248be64487d480
+            ctx.watch_tree(ctx.attr.path)
+        else:
+            print("""
+  WARNING: go.mod replace directives to module paths is only supported in bazel 7.1.0-rc1 or later,
+          Because of this changes to %s will not be detected by bazel in previous versions.""" % ctx.attr.path)
+
+        #
+        # TODO more advance syncing would be a better solution, but for now this is OK.
+        # purge directory:
+        command = ["rm", "-rf", "%s/" % ctx.path("")]
+        result = env_execute(
+            ctx,
+            command,
+            environment = local_path_env,
+            timeout = _GO_REPOSITORY_TIMEOUT,
+        )
+
+        if result.return_code:
+            fail(command)
+
+        if result.stderr:
+            print("clear mod: %s", result.stderr)
+
+        if result.return_code:
+            fail(command)
+
+        command = ["cp", "-r", "%s/" % ctx.attr.path, ctx.path("")]
+        result = env_execute(
+            ctx,
+            command,
+            environment = local_path_env,
+            timeout = _GO_REPOSITORY_TIMEOUT,
+        )
+
+        # use "go mod download" to satisfy the dependencies of this module
+        if ctx.attr.debug_mode and result.stderr:
+            print("copy mod: %s", result.stderr)
+
+        if result.return_code:
+            fail(command)
+
+        # TODO: this needs to have a go mod with the same go version as the
+        # project, or it may fail as not all go versions are available
+        # locally
+        command = ["go", "mod", "download", "-json", "-modcacherw"]
+        result = env_execute(
+            ctx,
+            command,
+            environment = local_path_env,
+            timeout = _GO_REPOSITORY_TIMEOUT,
+            working_directory = "%s" % ctx.path(""),
+        )
+
+        # use "go mod download" to satisfy the dependencies of this module
+        if result.stderr:
+            print("mod download: %s", result.stderr)
+
+        if result.return_code:
+            fail(command)
+
+        # use "go mod download" to satisfy the dependencies of this module
+
     if fetch_repo_args:
         # Disable sumdb in fetch_repo. In module mode, the sum is a mandatory
         # attribute of go_repository, so we don't need to look it up.
@@ -252,10 +325,12 @@ def _go_repository_impl(ctx):
             environment = fetch_repo_env,
             timeout = _GO_REPOSITORY_TIMEOUT,
         )
+
+        if result.stderr:
+            print("copy_repo: " + result.stderr)
+
         if result.return_code:
-            fail("failed to fetch %s: %s" % (ctx.name, result.stderr))
-        if ctx.attr.debug_mode and result.stderr:
-            print("fetch_repo: " + result.stderr)
+            fail("%s: %s" % (ctx.name, result.stderr))
 
     # Repositories are fetched. Determine if build file generation is needed.
     build_file_names = ctx.attr.build_file_name.split(",")
@@ -307,7 +382,7 @@ def _go_repository_impl(ctx):
             "-repo_config",
             repo_config,
         ]
-        if ctx.attr.version:
+        if ctx.attr.version or ctx.attr.path:
             cmd.append("-go_repository_module_mode")
         if ctx.attr.build_file_name:
             cmd.extend(["-build_file_name", ctx.attr.build_file_name])
@@ -421,6 +496,11 @@ go_repository = repository_rule(
             doc = _AUTH_PATTERN_DOC,
         ),
 
+        # Attributes for a module that should be loaded from the local file system.
+        "path": attr.string(
+            doc = """ If specified, `go_repository` will load the module from this local directory""",
+        ),
+
         # Attributes for a module that should be downloaded with the Go toolchain.
         "version": attr.string(
             doc = """If specified, `go_repository` will download the module at this version