link manifest: record CUDA runtime libs and toolkit search dirs

bindings/rust/sys/build.rs

@@ -365,6 +365,12 @@ fn emit_link_lines(prefix: &Path, manifest_path: &Path) {
     let lib_dir = prefix.join(json["lib_dir"].as_str().unwrap_or("lib"));
     println!("cargo:rustc-link-search=native={}", lib_dir.display());
 
+    // Extra linker search directories recorded at configure time (e.g. the
+    // CUDA toolkit's library dir, which is rarely on the default path).
+    for dir in strs("search_dirs") {
+        println!("cargo:rustc-link-search=native={dir}");
+    }
+
     // Archives (static) or the single shared lib. The manifest order is
     // single-pass-GNU-ld safe (each archive's undefined refs resolve in a
     // later one: transcribe -> ggml -> backends -> ggml-base).

cmake/transcribe-install.cmake

@@ -88,6 +88,7 @@ endif()
 set(_libraries transcribe)
 set(_library_paths "")
 set(_system_libs "")
+set(_search_dirs "")
 set(_frameworks "")
 set(_link_flags "")
 
@@ -137,6 +138,25 @@ if(NOT TRANSCRIBE_BUILD_SHARED)
     if("vulkan" IN_LIST _kinds)
         list(APPEND _system_libs vulkan)
     endif()
+    if("cuda" IN_LIST _kinds)
+        # The ggml-cuda archive references the CUDA runtime and cuBLAS and —
+        # unless VMM was disabled at configure time — the CUDA driver API
+        # (mirrors ggml/src/ggml-cuda/CMakeLists.txt). Record the toolkit's
+        # library directory too: it is rarely on the default linker path, so
+        # names alone leave every non-CMake consumer guessing an install
+        # root. The stubs directory satisfies `-lcuda` on machines that
+        # build without a display driver; at runtime the real libcuda
+        # resolves through the loader as usual.
+        find_package(CUDAToolkit REQUIRED)
+        list(APPEND _system_libs cudart cublas)
+        if(NOT GGML_CUDA_NO_VMM)
+            list(APPEND _system_libs cuda)
+        endif()
+        list(APPEND _search_dirs "${CUDAToolkit_LIBRARY_DIR}")
+        if(EXISTS "${CUDAToolkit_LIBRARY_DIR}/stubs")
+            list(APPEND _search_dirs "${CUDAToolkit_LIBRARY_DIR}/stubs")
+        endif()
+    endif()
     if(_frameworks)
         list(REMOVE_DUPLICATES _frameworks)
     endif()
@@ -184,6 +204,7 @@ endfunction()
 _transcribe_json_strings(_kinds_json ${_kinds})
 _transcribe_json_strings(_libraries_json ${_libraries})
 _transcribe_json_strings(_library_paths_json ${_library_paths})
+_transcribe_json_strings(_search_dirs_json ${_search_dirs})
 _transcribe_json_strings(_system_libs_json ${_system_libs})
 _transcribe_json_strings(_frameworks_json ${_frameworks})
 _transcribe_json_strings(_link_flags_json ${_link_flags})
@@ -201,6 +222,7 @@ file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/transcribe-link.json"
   \"lib_dir\": \"${CMAKE_INSTALL_LIBDIR}\",
   \"libraries\": [${_libraries_json}],
   \"library_paths\": [${_library_paths_json}],
+  \"search_dirs\": [${_search_dirs_json}],
   \"system_libs\": [${_system_libs_json}],
   \"frameworks\": [${_frameworks_json}],
   \"link_flags\": [${_link_flags_json}]

docs/bindings.md

@@ -35,11 +35,14 @@ binding's generated files:
 - **`lib/transcribe-link.json`** — installed by `cmake --install` (the
   `TRANSCRIBE_INSTALL` rules): the machine-readable link interface for
   non-CMake consumers building from source (the Rust `-sys` crate's
-  `build.rs`). Archive order, system libs, frameworks, flags, and — for
-  `GGML_BACKEND_DL` installs — `module_dir`, the directory to hand to
-  `transcribe_init_backends()`. Proven per push by the link-smoke CI lane,
-  which compiles a toy C consumer from nothing but this manifest in both
-  static and shared postures.
+  `build.rs`). Archive order, system libs, `search_dirs` (extra linker
+  search directories recorded at configure time — e.g. the CUDA toolkit's
+  library dir and its driver-stub subdirectory, which back the `cudart` /
+  `cublas` / `cuda` entries CUDA builds add to `system_libs`), frameworks,
+  flags, and — for `GGML_BACKEND_DL` installs — `module_dir`, the
+  directory to hand to `transcribe_init_backends()`. Proven per push by
+  the link-smoke CI lane, which compiles a toy C consumer from nothing but
+  this manifest in both static and shared postures.
 
 ## Result text pointers: copy at the FFI boundary
 

scripts/ci/link_smoke.py

@@ -49,6 +49,9 @@ def main() -> int:
     cmd = [args.cc, str(SOURCE), f"-I{include_dir}", "-o", str(out)]
     cmd += manifest["link_flags"]
     cmd += [f"-L{lib_dir}"]
+    # Configure-time search dirs (e.g. the CUDA toolkit's library dir);
+    # absent in pre-0.1.4 manifests.
+    cmd += [f"-L{path}" for path in manifest.get("search_dirs", [])]
 
     libs = [f"-l{name}" for name in manifest["libraries"]]
     if manifest["libraries"][1:] and platform.system() == "Linux":