Upgrade to nanobind 3

CMakeLists.txt

@@ -21,7 +21,7 @@ if (NOT SKBUILD)
   in your environment once and use the following command that avoids
   a costly creation of a new virtual environment at every compilation:
   =====================================================================
-    pip install nanobind scikit-build-core[pyproject]
+    pip install 'nanobind>=3.0.1,<4' scikit-build-core[pyproject]
     pip install --no-build-isolation -ve .
   =====================================================================
   You may optionally add -Ceditable.rebuild=true to auto-rebuild when

Makefile

@@ -43,7 +43,7 @@ install-python-dep: ## Installs the Python dependencies
 compile: check-system-dep ## Compiles the CUDA extension with nanobind
 	@echo "Compiling CUDA extension with nanobind..."
 	@echo "If you get an scikit-build-core error, you may need to 'uv cache clean' and 'trash build/'"
-	uv pip install scikit-build-core nanobind ninja cmake
+	uv pip install scikit-build-core 'nanobind>=3.0.1,<4' ninja cmake
 	uv sync --group build
 	# Not sure if the pip command is also needed
 	uv pip install -ve . --no-build-isolation

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["scikit-build-core>=0.10", "nanobind>=2.7"]
+requires = ["scikit-build-core>=0.10", "nanobind>=3.0.1,<4"]
 build-backend = "scikit_build_core.build"
 
 [project]
@@ -89,7 +89,7 @@ profile = [
 ]
 build = [
     "scikit-build-core>=0.10",
-    "nanobind>=2.7",
+    "nanobind>=3.0.1,<4",
     "cmake >=3.26.4",
     "ninja >=1.11.1",
 ]
@@ -212,6 +212,7 @@ preview = true
 [tool.pytest.ini_options]
 filterwarnings = [
     "error",  # make warnings errors
+    "ignore:.*No NVIDIA driver was found.*:RuntimeWarning",
     "ignore:.*This will add latency due to CPU<->GPU memory transfers.*:UserWarning",
     # vbeam warnings
     "ignore:point_position will be overwritten by the scan.:UserWarning",
@@ -236,7 +237,7 @@ build = [
 # build-requires explicitly.
 # because cibuildwheel uses Docker, we also need to use --system
 before-build = [
-    "uv pip install --system scikit-build-core>=0.10 nanobind>=2.7 ninja"
+    "uv pip install --system 'scikit-build-core>=0.10' 'nanobind>=3.0.1,<4' ninja"
 ]
 # Need --no-isolation to find nvcc
 build-frontend = { name = "build[uv]", args = ["--no-isolation"] }

src/mach/kernel.cu

@@ -352,14 +352,20 @@ static __device__ __forceinline__ float tukey_apod_weight(float r_norm, float al
  * @brief Check CUDA driver compatibility and warn if incompatible
  *
  * This function checks if the installed CUDA driver is compatible with the
- * NVCC version used to compile this module. Issues a warning if incompatible.
+ * NVCC version used to compile this module. Issues a warning if no driver is
+ * found or if the driver is incompatible.
  */
 static void checkCudaDriverCompatibility() {
     int driverVersion = 0;
 
-    // Get driver version - if this fails, let later CUDA operations handle the error
-    if (cudaDriverGetVersion(&driverVersion) != cudaSuccess) {
-        PyErr_WarnEx(PyExc_RuntimeWarning, "Could not get CUDA driver version", 1);
+    if (cudaDriverGetVersion(&driverVersion) != cudaSuccess || driverVersion == 0) {
+        // cudaDriverGetVersion reports 0 when no driver is installed
+        if (PyErr_WarnEx(
+                PyExc_RuntimeWarning,
+                "[mach] No NVIDIA driver was found. CUDA beamforming is unavailable.",
+                1) < 0) {
+            throw nb::python_error();
+        }
         return;
     }
 
@@ -384,7 +390,9 @@ static void checkCudaDriverCompatibility() {
         "→ Please update your NVIDIA driver to version " +
         std::to_string(nvccMajor) + "." + std::to_string(nvccMinor) + " or newer.";
 
-    PyErr_WarnEx(PyExc_RuntimeWarning, warning_msg.c_str(), 1);
+    if (PyErr_WarnEx(PyExc_RuntimeWarning, warning_msg.c_str(), 1) < 0) {
+        throw nb::python_error();
+    }
 }
 
 /**
@@ -418,7 +426,9 @@ static void checkComputeCapability() {
             std::to_string(MIN_CC_MAJOR) + "." + std::to_string(MIN_CC_MINOR) +
             ". Kernels may fail to load.";
 
-        PyErr_WarnEx(PyExc_RuntimeWarning, warning_msg.c_str(), 1);
+        if (PyErr_WarnEx(PyExc_RuntimeWarning, warning_msg.c_str(), 1) < 0) {
+            throw nb::python_error();
+        }
     }
 }