warn on unknown fields and confusable targets

CHANGELOG.md

@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- #681 - Warn on unknown fields and confusable targets
 - #665 - when not using [env.volumes](https://github.com/cross-rs/cross#mounting-volumes-into-the-build-environment), mount project in /project
 - #624 - Add `build.default-target`
 - #670 - Use serde for deserialization of Cross.toml

Cargo.toml

@@ -21,6 +21,7 @@ which = { version = "4", default_features = false }
 shell-escape = "0.1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+serde_ignored = "0.1.2"
 
 [target.'cfg(not(windows))'.dependencies]
 nix = "0.23"

src/config.rs

@@ -117,6 +117,25 @@ impl Config {
         }
     }
 
+    pub fn confusable_target(&self, target: &Target) {
+        if let Some(keys) = self.toml.as_ref().map(|t| t.targets.keys()) {
+            for mentioned_target in keys {
+                let mentioned_target_norm = mentioned_target
+                    .to_string()
+                    .replace(|c| c == '-' || c == '_', "")
+                    .to_lowercase();
+                let target_norm = target
+                    .to_string()
+                    .replace(|c| c == '-' || c == '_', "")
+                    .to_lowercase();
+                if mentioned_target != target && mentioned_target_norm == target_norm {
+                    eprintln!("Warning: a target named \"{mentioned_target}\" is mentioned in the Cross configuration, but the current specified target is \"{target}\".");
+                    eprintln!(" > Is the target misspelled in the Cross configuration?");
+                }
+            }
+        }
+    }
+
     #[cfg(test)]
     fn new_with(toml: Option<CrossToml>, env: Environment) -> Self {
         Config { toml, env }
@@ -293,6 +312,7 @@ mod tests {
         }
     }
 
+    #[cfg(test)]
     mod test_config {
 
         use super::*;

src/cross_toml.rs

@@ -39,14 +39,28 @@ pub struct CrossTargetConfig {
 #[derive(Debug, Deserialize, PartialEq)]
 pub struct CrossToml {
     #[serde(default, rename = "target")]
-    targets: HashMap<Target, CrossTargetConfig>,
-    build: Option<CrossBuildConfig>,
+    pub targets: HashMap<Target, CrossTargetConfig>,
+    pub build: Option<CrossBuildConfig>,
 }
 
 impl CrossToml {
     /// Parses the [`CrossToml`] from a string
     pub fn from_str(toml_str: &str) -> Result<Self> {
-        let cfg: CrossToml = toml::from_str(toml_str)?;
+        let tomld = &mut toml::Deserializer::new(toml_str);
+
+        let mut unused = std::collections::BTreeSet::new();
+
+        let cfg = serde_ignored::deserialize(tomld, |path| {
+            unused.insert(path.to_string());
+        })?;
+
+        if !unused.is_empty() {
+            eprintln!(
+                "Warning: found unused key(s) in Cross configuration:\n > {}",
+                unused.into_iter().collect::<Vec<_>>().join(", ")
+            );
+        }
+
         Ok(cfg)
     }
 

src/main.rs

@@ -276,7 +276,7 @@ fn run() -> Result<ExitStatus> {
             .target
             .or_else(|| config.target(&target_list))
             .unwrap_or_else(|| Target::from(host.triple(), &target_list));
-
+        config.confusable_target(&target);
         if host.is_supported(Some(&target)) {
             let mut sysroot = rustc::sysroot(&host, &target, verbose)?;
             let default_toolchain = sysroot