Make match_wild_err_arm pedantic, and update help messages

clippy_lints/src/lib.rs

@@ -1139,6 +1139,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&macro_use::MACRO_USE_IMPORTS),
         LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS),
         LintId::of(&matches::MATCH_BOOL),
+        LintId::of(&matches::MATCH_WILD_ERR_ARM),
         LintId::of(&matches::SINGLE_MATCH_ELSE),
         LintId::of(&methods::FILTER_MAP),
         LintId::of(&methods::FILTER_MAP_NEXT),
@@ -1283,7 +1284,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&matches::MATCH_OVERLAPPING_ARM),
         LintId::of(&matches::MATCH_REF_PATS),
         LintId::of(&matches::MATCH_SINGLE_BINDING),
-        LintId::of(&matches::MATCH_WILD_ERR_ARM),
         LintId::of(&matches::SINGLE_MATCH),
         LintId::of(&matches::WILDCARD_IN_OR_PATTERNS),
         LintId::of(&mem_discriminant::MEM_DISCRIMINANT_NON_ENUM),
@@ -1474,7 +1474,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH),
         LintId::of(&matches::MATCH_OVERLAPPING_ARM),
         LintId::of(&matches::MATCH_REF_PATS),
-        LintId::of(&matches::MATCH_WILD_ERR_ARM),
         LintId::of(&matches::SINGLE_MATCH),
         LintId::of(&mem_replace::MEM_REPLACE_OPTION_WITH_NONE),
         LintId::of(&mem_replace::MEM_REPLACE_WITH_DEFAULT),

clippy_lints/src/matches.rs

@@ -168,7 +168,7 @@ declare_clippy_lint! {
     /// **What it does:** Checks for arm which matches all errors with `Err(_)`
     /// and take drastic actions like `panic!`.
     ///
-    /// **Why is this bad?** It is generally a bad practice, just like
+    /// **Why is this bad?** It is generally a bad practice, similar to
     /// catching all exceptions in java with `catch(Exception)`
     ///
     /// **Known problems:** None.
@@ -182,7 +182,7 @@ declare_clippy_lint! {
     /// }
     /// ```
     pub MATCH_WILD_ERR_ARM,
-    style,
+    pedantic,
     "a `match` with `Err(_)` arm and take drastic actions"
 }
 
@@ -676,7 +676,7 @@ fn check_wild_err_arm(cx: &LateContext<'_, '_>, ex: &Expr<'_>, arms: &[Arm<'_>])
                                 arm.pat.span,
                                 &format!("`Err({})` matches all errors", &ident_bind_name),
                                 None,
-                                "match each error separately or use the error output",
+                                "match each error separately or use the error output, or use `.except(msg)` if the error case is unreachable",
                             );
                         }
                     }

src/lintlist/mod.rs

@@ -1195,7 +1195,7 @@ pub static ref ALL_LINTS: Vec<Lint> = vec![
     },
     Lint {
         name: "match_wild_err_arm",
-        group: "style",
+        group: "pedantic",
         desc: "a `match` with `Err(_)` arm and take drastic actions",
         deprecation: None,
         module: "matches",

tests/ui/match_wild_err_arm.stderr

@@ -5,31 +5,31 @@ LL |         Err(_) => panic!("err"),
    |         ^^^^^^
    |
    = note: `-D clippy::match-wild-err-arm` implied by `-D warnings`
-   = note: match each error separately or use the error output
+   = note: match each error separately or use the error output, or use `.except(msg)` if the error case is unreachable
 
 error: `Err(_)` matches all errors
   --> $DIR/match_wild_err_arm.rs:17:9
    |
 LL |         Err(_) => panic!(),
    |         ^^^^^^
    |
-   = note: match each error separately or use the error output
+   = note: match each error separately or use the error output, or use `.except(msg)` if the error case is unreachable
 
 error: `Err(_)` matches all errors
   --> $DIR/match_wild_err_arm.rs:23:9
    |
 LL |         Err(_) => {
    |         ^^^^^^
    |
-   = note: match each error separately or use the error output
+   = note: match each error separately or use the error output, or use `.except(msg)` if the error case is unreachable
 
 error: `Err(_e)` matches all errors
   --> $DIR/match_wild_err_arm.rs:31:9
    |
 LL |         Err(_e) => panic!(),
    |         ^^^^^^^
    |
-   = note: match each error separately or use the error output
+   = note: match each error separately or use the error output, or use `.except(msg)` if the error case is unreachable
 
 error: aborting due to 4 previous errors