Fix issue #304

Author: Michael Wright

src/rustup-utils/src/utils.rs

@@ -326,6 +326,19 @@ pub fn remove_file(name: &'static str, path: &Path) -> Result<()> {
     })
 }
 
+pub fn ensure_file_removed(name: &'static str, path: &Path) -> Result<()> {
+    let result = fs::remove_file(path);
+    if let Err(err) = &result {
+        if err.kind() == io::ErrorKind::NotFound {
+            return Ok(())
+        }
+    }
+    result.chain_err(|| ErrorKind::RemovingFile {
+        name: name,
+        path: PathBuf::from(path),
+    })
+}
+
 pub fn read_dir(name: &'static str, path: &Path) -> Result<fs::ReadDir> {
     fs::read_dir(path).chain_err(|| ErrorKind::ReadingDirectory {
         name: name,

src/rustup/toolchain.rs

@@ -94,7 +94,7 @@ impl<'a> Toolchain<'a> {
             return Ok(());
         }
         if let Some(update_hash) = self.update_hash()? {
-            utils::remove_file("update hash", &update_hash)?;
+            utils::ensure_file_removed("update hash", &update_hash)?;
         }
         let result = install::uninstall(&self.path, &|n| (self.cfg.notify_handler)(n.into()));
         if !self.exists() {

tests/cli-v2.rs

@@ -783,6 +783,20 @@ fn remove_target_host() {
     });
 }
 
+#[test]
+// Issue #304
+fn remove_target_missing_update_hash() {
+    setup(&|config| {
+
+        expect_ok(config, &["rustup", "update", "nightly"]);
+
+        let file_name = format!("nightly-{}", this_host_triple());
+        fs::remove_file(config.rustupdir.join("update-hashes").join(file_name)).unwrap();
+
+        expect_ok(config, &["rustup", "toolchain", "remove", "nightly"]);
+    });
+}
+
 fn make_component_unavailable(config: &Config, name: &str, target: &TargetTriple) {
     use rustup_dist::manifest::Manifest;
     use rustup_mock::dist::create_hash;