give ICE a proper error type

crates/nu-engine/src/compile/mod.rs

@@ -591,36 +591,25 @@ enum CompileError {
 
 impl CompileError {
     fn to_shell_error(self, mut span: Option<Span>) -> ShellError {
-        let ice = "internal compiler error: ";
         let message = match self {
-            CompileError::RegisterOverflow => format!("{ice}register overflow"),
+            CompileError::RegisterOverflow => format!("register overflow"),
             CompileError::RegisterUninitialized(reg_id) => {
-                format!("{ice}register {reg_id} is uninitialized when used, possibly reused")
+                format!("register {reg_id} is uninitialized when used, possibly reused")
             }
             CompileError::InvalidRedirectMode => {
-                format!("{ice}invalid redirect mode: File should not be specified by commands")
+                "invalid redirect mode: File should not be specified by commands".into()
-            }
-            CompileError::Garbage => {
-                format!("{ice}encountered garbage, likely due to parse error")
-            }
-            CompileError::UnsupportedOperatorExpression => {
-                format!("{ice}unsupported operator expression")
             }
+            CompileError::Garbage => "encountered garbage, likely due to parse error".into(),
+            CompileError::UnsupportedOperatorExpression => "unsupported operator expression".into(),
             CompileError::AccessEnvByInt(local_span) => {
                 span = Some(local_span);
-                format!("{ice}attempted access of $env by integer path")
+                "attempted access of $env by integer path".into()
             }
             CompileError::Todo(msg) => {
-                format!("{ice}TODO: {msg}")
+                format!("TODO: {msg}")
             }
         };
-        ShellError::GenericError {
+        ShellError::IrCompileError { message, span }
-            error: message,
-            msg: "while compiling this code".into(),
-            span,
-            help: Some("this is a bug, please report it at https://github.com/nushell/nushell/issues/new along with the code you were compiling if able".into()),
-            inner: vec![]
-        }
     }
 }
 

crates/nu-protocol/src/errors/shell_error.rs

@@ -1369,6 +1369,23 @@ On Windows, this would be %USERPROFILE%\AppData\Roaming"#
         help("Set XDG_CONFIG_HOME to an absolute path, or set it to an empty string to ignore it")
     )]
     InvalidXdgConfig { xdg: String, default: String },
+
+    /// An error occurred with the IR compiler.
+    ///
+    /// ## Resolution
+    ///
+    /// The IR compiler is in very early development, so code that can't be compiled is quite
+    /// expected. If you think it should be working, please report it to us.
+    #[error("internal compiler error: {message}")]
+    #[diagnostic(
+        code(nu::shell::ir_compile_error),
+        help("this is a bug, please report it at https://github.com/nushell/nushell/issues/new along with the code you were compiling if able")
+    )]
+    IrCompileError {
+        message: String,
+        #[label = "while compiling this code"]
+        span: Option<Span>,
+    },
 }
 
 // TODO: Implement as From trait