2 files changed, 15 insertions, 4 deletions

diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index d71b7031a..b7f6a9b57 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -23,9 +23,19 @@ pub use crate::{
     sysroot::Sysroot,
 };
 
-// FIXME use proper error enum
 pub type Result<T> = ::std::result::Result<T, Box<dyn Error + Send + Sync>>;
 
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub struct CargoTomlNotFoundError(pub PathBuf);
+
+impl std::fmt::Display for CargoTomlNotFoundError {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(fmt, "can't find Cargo.toml at {}", self.0.display())
+    }
+}
+
+impl Error for CargoTomlNotFoundError {}
+
 #[derive(Debug, Clone)]
 pub enum ProjectWorkspace {
     /// Project workspace was discovered by running `cargo metadata` and `rustc --print sysroot`.
@@ -362,7 +372,7 @@ fn find_cargo_toml(path: &Path) -> Result<PathBuf> {
         }
         curr = path.parent();
     }
-    Err(format!("can't find Cargo.toml at {}", path.display()))?
+    Err(CargoTomlNotFoundError(path.to_path_buf()))?
 }
 
 pub fn get_rustc_cfg_options() -> CfgOptions {
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 10ca391b6..34d066b1e 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -53,9 +53,10 @@ impl Sysroot {
         if !src.exists() {
             Err(format!(
                 "can't load standard library from sysroot\n\
-                 {:?}\n\
+                 {}\n\
+                 (discovered via `rustc --print sysroot`)\n\
                  try running `rustup component add rust-src` or set `RUST_SRC_PATH`",
-                src,
+                src.display(),
             ))?;
         }