fix(index): migrate mcpplibs index URL to mcpplibs org (#267-A)

The index repo moved from mcpp-community to the mcpplibs org; the old URL
only worked via GitHub's repo redirect. Centralize the canonical/legacy
URLs as constants, rewrite the URL in canonicalize_legacy_index_names
(URL first, so legacy name entries still match and legacy/default entries
fold in dedup), heal persisted config.toml/.xlings.json via the existing
text migrations, and update the publish fork hint + docs links.
canonicalize_legacy_index_names is now exported so ordering stays tested.

Author: Sunrisepeak

docs/00-getting-started.md

@@ -95,7 +95,7 @@ Declare dependencies in `mcpp.toml`:
 ```
 
 `mcpp build` automatically resolves SemVer constraints against the
-[mcpp-index](https://github.com/mcpp-community/mcpp-index), fetches the source,
+[mcpp-index](https://github.com/mcpplibs/mcpp-index), fetches the source,
 and adds it to the build graph. For a complete example, see `02-with-deps` in
 [01 — Examples](01-examples.md).
 

docs/04-build-from-source.md

@@ -93,5 +93,5 @@ mcpp is in early iteration and its interfaces may change. Before submitting a PR
 
 - [Community forum](https://forum.d2learn.org/category/20)
 - Chat group QQ: 1067245099
-- [mcpp-index](https://github.com/mcpp-community/mcpp-index) — the default package index
+- [mcpp-index](https://github.com/mcpplibs/mcpp-index) — the default package index
 - [mcpplibs](https://github.com/mcpplibs) — the companion collection of modular C++ libraries

docs/zh/00-getting-started.md

@@ -96,7 +96,7 @@ mcpp test               # 编译并运行 tests/**/*.cpp(gtest 风格)
 ```
 
 `mcpp build` 将自动从
-[mcpp-index](https://github.com/mcpp-community/mcpp-index) 解析 SemVer
+[mcpp-index](https://github.com/mcpplibs/mcpp-index) 解析 SemVer
 约束、拉取源码并加入编译图。完整示例参见
 [01 — 示例项目](01-examples.md) 中的 `02-with-deps`。
 

docs/zh/04-build-from-source.md

@@ -100,5 +100,5 @@ mcpp 处于早期迭代阶段,接口可能调整,提交 PR 前请注意:
 
 - [社区论坛](https://forum.d2learn.org/category/20)
 - 交流群 QQ: 1067245099
-- [mcpp-index](https://github.com/mcpp-community/mcpp-index) — 默认包索引
+- [mcpp-index](https://github.com/mcpplibs/mcpp-index) — 默认包索引
 - [mcpplibs](https://github.com/mcpplibs) — 配套的模块化 C++ 库集合

src/config.cppm

@@ -38,6 +38,18 @@ struct IndexRepo {
     std::string url;
 };
 
+// Canonical mcpplibs index coordinates. The index repository moved from the
+// mcpp-community org to the mcpplibs org (#267) — the legacy URL only works
+// through GitHub's repo redirect, which breaks silently if the old name is
+// ever re-taken. The artifact base is the release mirror consumed by
+// xlings >= 0.4.68 per-repo artifact sync (#269); older xlings ignores it.
+inline constexpr std::string_view kMcpplibsIndexUrl =
+    "https://github.com/mcpplibs/mcpp-index.git";
+inline constexpr std::string_view kMcpplibsIndexUrlLegacy =
+    "https://github.com/mcpp-community/mcpp-index.git";
+inline constexpr std::string_view kMcpplibsIndexArtifact =
+    "https://github.com/xlings-res/mcpp-index";
+
 struct GlobalConfig {
     // Resolved paths
     std::filesystem::path           mcppHome;            // ~/.mcpp/
@@ -251,6 +263,12 @@ std::expected<GlobalConfig, ConfigError> load_or_init(
 // Pretty-print resolved config for `mcpp env` command.
 void print_env(const GlobalConfig& cfg);
 
+// Normalize legacy index naming in a loaded config (exported for tests):
+// org migration mcpp-community/mcpp-index -> mcpplibs/mcpp-index, index name
+// mcpp-index -> mcpplibs, then name+url dedup. Order matters: URL first, so
+// old-config name entries still match and legacy/default entries fold.
+void canonicalize_legacy_index_names(GlobalConfig& cfg);
+
 // M5.5: persist [toolchain].default to config.toml.
 std::expected<void, ConfigError>
 write_default_toolchain(const GlobalConfig& cfg, std::string_view spec);
@@ -357,7 +375,7 @@ home   = ""
 default = "mcpplibs"
 
 [index.repos."mcpplibs"]
-url = "https://github.com/mcpp-community/mcpp-index.git"
+url = "https://github.com/mcpplibs/mcpp-index.git"
 # xlings auto-adds xim / awesome / scode / d2x as defaults.
 
 [cache]
@@ -396,25 +414,8 @@ bool write_default_xlings_json(const std::filesystem::path& path,
 }
 
 // Migration helpers delegated to mcpp.fallback.config_migration.
-
-void canonicalize_legacy_index_names(GlobalConfig& cfg) {
-    if (cfg.defaultIndex == "mcpp-index")
-        cfg.defaultIndex = "mcpplibs";
-
-    std::vector<IndexRepo> normalized;
-    for (auto r : cfg.indexRepos) {
-        if (r.name == "mcpp-index"
-            && r.url == "https://github.com/mcpp-community/mcpp-index.git") {
-            r.name = "mcpplibs";
-        }
-        bool duplicate = std::any_of(normalized.begin(), normalized.end(),
-            [&](const IndexRepo& existing) {
-                return existing.name == r.name && existing.url == r.url;
-            });
-        if (!duplicate) normalized.push_back(std::move(r));
-    }
-    cfg.indexRepos = std::move(normalized);
-}
+// canonicalize_legacy_index_names is exported (declared above, defined after
+// this helper namespace) so its ordering rules stay under unit test.
 
 // Xlings binary acquisition delegated to mcpp.fallback.xlings_binary.
 
@@ -454,6 +455,29 @@ void ensure_sandbox_patchelf(const GlobalConfig& cfg, bool quiet,
 
 } // namespace
 
+void canonicalize_legacy_index_names(GlobalConfig& cfg) {
+    if (cfg.defaultIndex == "mcpp-index")
+        cfg.defaultIndex = "mcpplibs";
+
+    std::vector<IndexRepo> normalized;
+    for (auto r : cfg.indexRepos) {
+        // ① Org migration first — later steps (name match, dedup) key on the
+        // canonical URL, so legacy entries fold instead of surviving as dupes.
+        if (r.url == kMcpplibsIndexUrlLegacy)
+            r.url = std::string(kMcpplibsIndexUrl);
+        // ② Legacy index name. The URL condition keeps a user's unrelated
+        // repo that happens to be named "mcpp-index" untouched.
+        if (r.name == "mcpp-index" && r.url == kMcpplibsIndexUrl)
+            r.name = "mcpplibs";
+        bool duplicate = std::any_of(normalized.begin(), normalized.end(),
+            [&](const IndexRepo& existing) {
+                return existing.name == r.name && existing.url == r.url;
+            });
+        if (!duplicate) normalized.push_back(std::move(r));
+    }
+    cfg.indexRepos = std::move(normalized);
+}
+
 std::expected<GlobalConfig, ConfigError> load_or_init(
     bool quiet,
     BootstrapProgressCallback onBootstrapProgress,
@@ -572,7 +596,7 @@ std::expected<GlobalConfig, ConfigError> load_or_init(
         for (auto& r : cfg.indexRepos) if (r.name == name) return;
         cfg.indexRepos.push_back({ std::string(name), std::string(url) });
     };
-    add_default("mcpplibs", "https://github.com/mcpp-community/mcpp-index.git");
+    add_default("mcpplibs", kMcpplibsIndexUrl);
     canonicalize_legacy_index_names(cfg);
 
     // 5. Seed registry/.xlings.json if missing; migrate legacy cached

src/fallback/config_migration.cppm

@@ -62,6 +62,9 @@ bool migrate_config_toml_index_names(const std::filesystem::path& path) {
 
     replace_all(updated, "default = \"mcpp-index\"", "default = \"mcpplibs\"");
     replace_all(updated, "[index.repos.\"mcpp-index\"]", "[index.repos.\"mcpplibs\"]");
+    // Org migration (#267): the index repo moved to the mcpplibs org.
+    replace_all(updated, "https://github.com/mcpp-community/mcpp-index.git",
+                         "https://github.com/mcpplibs/mcpp-index.git");
 
     return write_text_if_changed(path, original, updated);
 }
@@ -76,6 +79,9 @@ bool migrate_xlings_json_index_names(const std::filesystem::path& path) {
 
     replace_all(updated, "\"name\": \"mcpp-index\"", "\"name\": \"mcpplibs\"");
     replace_all(updated, "\"name\":\"mcpp-index\"", "\"name\":\"mcpplibs\"");
+    // Org migration (#267): the index repo moved to the mcpplibs org.
+    replace_all(updated, "https://github.com/mcpp-community/mcpp-index.git",
+                         "https://github.com/mcpplibs/mcpp-index.git");
 
     return write_text_if_changed(path, original, updated);
 }

src/publish/pipeline.cppm

@@ -155,7 +155,7 @@ export int publish_package(bool dry_run, bool allow_dirty) {
     std::println("       Attach: {}", tarball.string());
     std::println("");
     std::println("  3. Open a PR to mcpp-index:");
-    std::println("       Fork:  https://github.com/mcpp-community/mcpp-index");
+    std::println("       Fork:  https://github.com/mcpplibs/mcpp-index");
     std::println("       Add:   pkgs/{}/{}.lua", first, pkg.name);
     std::println("       (file content is in {})", xpkgPath.string());
     std::println("");

tests/unit/test_config.cpp

@@ -5,6 +5,7 @@
 
 import std;
 import mcpp.config;
+import mcpp.fallback.config_migration;
 import mcpp.pm.index_spec;
 
 namespace {
@@ -162,3 +163,63 @@ TEST(Config, ProjectLocalIndexStaleCacheIsRemoved) {
 
     std::filesystem::remove_all(project);
 }
+
+// ── #267-A/#269: index org migration + artifact adoption ────────────────────
+
+namespace {
+
+std::string read_all(const std::filesystem::path& p) {
+    std::stringstream ss;
+    ss << std::ifstream(p).rdbuf();
+    return ss.str();
+}
+
+}  // namespace
+
+TEST(ConfigIndexMigration, CanonicalizeRewritesOrgAndName) {
+    mcpp::config::GlobalConfig cfg;
+    cfg.defaultIndex = "mcpp-index";
+    cfg.indexRepos.push_back({ "mcpp-index",
+        std::string(mcpp::config::kMcpplibsIndexUrlLegacy) });
+    mcpp::config::canonicalize_legacy_index_names(cfg);
+    ASSERT_EQ(cfg.indexRepos.size(), 1u);
+    EXPECT_EQ(cfg.defaultIndex, "mcpplibs");
+    EXPECT_EQ(cfg.indexRepos[0].name, "mcpplibs");
+    EXPECT_EQ(cfg.indexRepos[0].url,  mcpp::config::kMcpplibsIndexUrl);
+}
+
+TEST(ConfigIndexMigration, CanonicalizeFoldsLegacyAndDefaultEntries) {
+    mcpp::config::GlobalConfig cfg;
+    cfg.indexRepos.push_back({ "mcpplibs",
+        std::string(mcpp::config::kMcpplibsIndexUrlLegacy) });
+    cfg.indexRepos.push_back({ "mcpplibs",
+        std::string(mcpp::config::kMcpplibsIndexUrl) });
+    mcpp::config::canonicalize_legacy_index_names(cfg);
+    EXPECT_EQ(cfg.indexRepos.size(), 1u);
+}
+
+TEST(ConfigIndexMigration, CanonicalizeLeavesForeignReposAlone) {
+    mcpp::config::GlobalConfig cfg;
+    cfg.indexRepos.push_back({ "other", "https://example.com/other-index.git" });
+    mcpp::config::canonicalize_legacy_index_names(cfg);
+    ASSERT_EQ(cfg.indexRepos.size(), 1u);
+    EXPECT_EQ(cfg.indexRepos[0].name, "other");
+    EXPECT_EQ(cfg.indexRepos[0].url, "https://example.com/other-index.git");
+}
+
+TEST(ConfigIndexMigration, MigrateConfigTomlRewritesOrgUrlIdempotently) {
+    auto dir = make_tempdir("mcpp-migrate-toml");
+    auto p = dir / "config.toml";
+    {
+        std::ofstream os(p);
+        os << "[index]\ndefault = \"mcpplibs\"\n\n[index.repos.\"mcpplibs\"]\n"
+              "url = \"https://github.com/mcpp-community/mcpp-index.git\"\n";
+    }
+    EXPECT_TRUE(mcpp::fallback::migrate_config_toml_index_names(p));
+    auto text = read_all(p);
+    EXPECT_NE(text.find("github.com/mcpplibs/mcpp-index.git"), std::string::npos);
+    EXPECT_EQ(text.find("mcpp-community/mcpp-index"), std::string::npos);
+    EXPECT_FALSE(mcpp::fallback::migrate_config_toml_index_names(p));  // idempotent
+    EXPECT_EQ(read_all(p), text);
+    std::filesystem::remove_all(dir);
+}