Fix clippy warning: use #[non_exhaustive] instead of manually reimplementing it

Author: jyn514

src/cmd/mod.rs

@@ -59,6 +59,7 @@ pub(crate) mod container_dirs {
 
 /// Error happened while executing a command.
 #[derive(Debug, Fail)]
+#[non_exhaustive]
 pub enum CommandError {
     /// The command didn't output anything to stdout or stderr for more than the timeout, and it
     /// was killed. The timeout's value (in seconds) is the first value.
@@ -71,12 +72,10 @@ pub enum CommandError {
     /// The sandbox ran out of memory and was killed.
     #[fail(display = "container ran out of memory")]
     SandboxOOM,
-    #[doc(hidden)]
-    #[fail(display = "this error shouldn't have happened")]
-    __NonExaustive,
 }
 
 /// Name and kind of a binary executed by [`Command`](struct.Command.html).
+#[non_exhaustive]
 pub enum Binary {
     /// Global binary, available in `$PATH`. Rustwide doesn't apply any tweaks to its execution
     /// environment.
@@ -85,8 +84,6 @@ pub enum Binary {
     /// tweak the environment to use the local rustup instead of the host system one, and will
     /// search the binary in the cargo home.
     ManagedByRustwide(PathBuf),
-    #[doc(hidden)]
-    __NonExaustive,
 }
 
 /// Trait representing a command that can be run by [`Command`](struct.Command.html).
@@ -313,7 +310,6 @@ impl<'w, 'pl> Command<'w, 'pl> {
                 Binary::ManagedByRustwide(path) => {
                     container_dirs::CARGO_BIN_DIR.join(exe_suffix(path.as_os_str()))
                 }
-                Binary::__NonExaustive => panic!("do not create __NonExaustive variants manually"),
             };
 
             let mut cmd = Vec::new();
@@ -382,7 +378,6 @@ impl<'w, 'pl> Command<'w, 'pl> {
                     // `cargo_home()` might a relative path
                     (crate::utils::normalize_path(&binary), true)
                 }
-                Binary::__NonExaustive => panic!("do not create __NonExaustive variants manually"),
             };
 
             let mut cmd = AsyncCommand::new(&binary);

src/cmd/sandbox.rs

@@ -69,13 +69,12 @@ impl SandboxImage {
 
 /// Whether to mount a path in the sandbox with write permissions or not.
 #[derive(Copy, Clone, PartialEq, Eq)]
+#[non_exhaustive]
 pub enum MountKind {
     /// Allow the sandboxed code to change the mounted data.
     ReadWrite,
     /// Prevent the sandboxed code from changing the mounted data.
     ReadOnly,
-    #[doc(hidden)]
-    __NonExaustive,
 }
 
 #[derive(Clone)]
@@ -108,7 +107,6 @@ impl MountConfig {
         let perm = match self.perm {
             MountKind::ReadWrite => "rw",
             MountKind::ReadOnly => "ro",
-            MountKind::__NonExaustive => panic!("do not create __NonExaustive variants manually"),
         };
         Ok(format!(
             "{}:{}:{},Z",

src/prepare.rs

@@ -373,6 +373,7 @@ impl<'a> TomlTweaker<'a> {
 
 /// Error happened while preparing a crate for a build.
 #[derive(Debug, Fail)]
+#[non_exhaustive]
 pub enum PrepareError {
     /// The git repository isn't publicly available.
     #[fail(display = "can't fetch private git repositories")]
@@ -387,9 +388,6 @@ pub enum PrepareError {
     /// Some of this crate's dependencies were yanked, preventing Crater from fetching them.
     #[fail(display = "the crate depends on yanked dependencies")]
     YankedDependencies,
-    #[doc(hidden)]
-    #[fail(display = "this error shouldn't have happened")]
-    __NonExaustive,
 }
 
 #[cfg(test)]