fixes

interfaces/Crafter.Build-External.cppm

@@ -24,6 +24,8 @@ import std;
 namespace fs = std::filesystem;
 
 export namespace Crafter {
+    struct Configuration;
+
     struct GitSource {
         std::string url;
         std::string branch;
@@ -55,4 +57,37 @@ export namespace Crafter {
         const ExternalDependency& dep,
         std::string_view target,
         std::atomic<bool>& cancelled);
+
+    // Specification for a sibling crafter-build project to fetch and depend on.
+    // GitSource picks the revision: leave branch + commit empty for the
+    // remote's default branch HEAD (sloppy but convenient), set branch to
+    // track a branch tip, or set commit to pin to an immutable SHA. args are
+    // forwarded verbatim to the dep's CrafterBuildProject — typically you
+    // pass through the parent's args so target/march/debug propagate.
+    struct GitProjectSpec {
+        GitSource source;
+        fs::path projectFile = "project.cpp";
+        std::vector<std::string> args;
+    };
+
+    // Clones the spec's git URL into the per-project external cache (keyed by
+    // url+branch+commit+args+projectFile), recursively LoadProject's the
+    // remote's project.cpp, and returns a stable Configuration* you can drop
+    // into cfg.dependencies. The Configuration is owned by an internal cache
+    // for the lifetime of the build; identical specs share one Configuration.
+    CRAFTER_API Configuration* GitProject(const GitProjectSpec& spec);
+
+    // Specification for a local sibling crafter-build project (e.g. an
+    // example folder depending on its parent project, or a workspace where
+    // multiple projects live side-by-side without going through git).
+    struct LocalProjectSpec {
+        fs::path projectFile;             // relative to cwd or absolute
+        std::vector<std::string> args;    // forwarded to dep's CrafterBuildProject
+    };
+
+    // Same as GitProject but for a local on-disk project — no fetch, no
+    // cache copy. Resolves projectFile to its canonical absolute path and
+    // recursively LoadProject's it. Returns a stable Configuration* owned
+    // by the same internal cache as GitProject.
+    CRAFTER_API Configuration* LocalProject(const LocalProjectSpec& spec);
 }