Always link ctru, for now

Also add a little extra description helper for unknown error types in
ctru::error

ctru-rs/src/error.rs

@@ -256,7 +256,13 @@ fn result_code_description_str(result: ctru_sys::Result) -> Cow<'static, str> {
         RD_NOT_AUTHORIZED => "not_authorized",
         RD_TOO_LARGE => "too_large",
         RD_INVALID_SELECTION => "invalid_selection",
-        code => return Cow::Owned(format!("(unknown description: {code:#x})")),
+        code => {
+            let error = unsafe { CStr::from_ptr(ctru_sys::osStrError(result)) }.to_str();
+            match error {
+                Ok(err) => err,
+                Err(_) => return Cow::Owned(format!("(unknown description: {code:#x})")),
+            }
+        }
     })
 }
 

ctru-sys/Cargo.toml

@@ -21,6 +21,10 @@ doxygen-rs = "0.4.2"
 itertools = "0.11.0"
 which = "4.4.0"
 
+[dev-dependencies]
+shim-3ds = { git = "https://github.com/rust3ds/shim-3ds.git" }
+test-runner = { git = "https://github.com/rust3ds/test-runner.git" }
+
 [package.metadata.docs.rs]
 default-target = "armv6k-nintendo-3ds"
 targets = []

ctru-sys/build.rs

@@ -19,19 +19,28 @@ impl ParseCallbacks for CustomCallbacks {
 fn main() {
     let devkitpro = env::var("DEVKITPRO").unwrap();
     let devkitarm = env::var("DEVKITARM").unwrap();
-    let profile = env::var("PROFILE").unwrap();
+    let debuginfo = env::var("DEBUG").unwrap();
     let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
 
     println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rerun-if-env-changed=DEVKITPRO");
     println!("cargo:rustc-link-search=native={devkitpro}/libctru/lib");
-    println!(
-        "cargo:rustc-link-lib=static={}",
-        match profile.as_str() {
-            "debug" => "ctrud",
-            _ => "ctru",
-        }
-    );
+
+    let linked_libctru = match debuginfo.as_str() {
+        // Normally this should just be "true" or "false", but just in case,
+        // we don't support all the different options documented in
+        // https://doc.rust-lang.org/cargo/reference/profiles.html#debug
+        // so just default to linking with debuginfo if it wasn't disabled
+        "0" | "false" | "none" => "ctru",
+        // TODO https://github.com/rust3ds/cargo-3ds/issues/14#issuecomment-1783991872
+        // To link properly, this must be the same as the library linked by cargo-3ds
+        // building the standard library,  which is always `ctru` in practice.
+        // Ideally we should link `ctrud` if debug symbols are requested though:
+        _ => "ctru",
+        // _ => "ctrud",
+    };
+
+    println!("cargo:rustc-link-lib=static={linked_libctru}");
 
     detect_and_track_libctru();
 

ctru-sys/src/lib.rs

@@ -3,6 +3,8 @@
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
 #![allow(clippy::all)]
+#![cfg_attr(test, feature(custom_test_frameworks))]
+#![cfg_attr(test, test_runner(test_runner::run_gdb))]
 
 pub mod result;
 pub use result::*;
@@ -15,10 +17,6 @@ pub unsafe fn errno() -> s32 {
     *__errno()
 }
 
-// TODO: not sure if there's a better way to do this, but I have gotten myself
-// with this a couple times so having the hint seems nice to have.
+// Prevent linking errors from the standard `test` library when running `cargo 3ds test --lib`.
 #[cfg(test)]
-compile_error!(concat!(
-    "ctru-sys doesn't have tests and its lib test will fail to build at link time. ",
-    "Try specifying `--package ctru-rs` to build those tests.",
-));
+extern crate shim_3ds;