Looking for dependencies on test for a better UX

build.rs

@@ -0,0 +1,38 @@
+// build.rs -- Compile-time detection of optional build tools.
+//
+// Sets cfg flags that integration tests use to gracefully skip when
+// tools are missing instead of panicking with scary error messages.
+//
+//   has_cmake          cmake is in PATH
+//   has_cpp_compiler   g++, clang++, or cl is in PATH
+//   has_git            git is in PATH
+//   has_arduino_cli    arduino-cli is in PATH
+//
+// Usage in tests:
+//   #[cfg_attr(not(has_cmake), ignore = "cmake not found")]
+
+use std::process::{Command, Stdio};
+
+fn has_tool(name: &str) -> bool {
+    Command::new(name)
+        .arg("--version")
+        .stdout(Stdio::null())
+        .stderr(Stdio::null())
+        .status()
+        .is_ok()
+}
+
+fn main() {
+    if has_tool("cmake") {
+        println!("cargo:rustc-cfg=has_cmake");
+    }
+    if has_tool("g++") || has_tool("clang++") || has_tool("cl") {
+        println!("cargo:rustc-cfg=has_cpp_compiler");
+    }
+    if has_tool("git") {
+        println!("cargo:rustc-cfg=has_git");
+    }
+    if has_tool("arduino-cli") {
+        println!("cargo:rustc-cfg=has_arduino_cli");
+    }
+}