- Parse error in $defined was not handled correctly, leading to an assertion.

releasenotes.md

@@ -37,6 +37,7 @@
 - Compiler assert when passing returning CT failure immediately rethrown #2689.
 - Converting between simd/non-simd bool vector would hit a compiler assert. #2691
 - `i<n>` suffixes were not caught when n < 8, causing an assert.
+- Parse error in `$defined` was not handled correctly, leading to an assertion.
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.

src/compiler/parse_expr.c

@@ -1209,7 +1209,7 @@ static Expr *parse_ct_defined(ParseContext *c, Expr *left, SourceSpan lhs_start
 		vec_add(defined->expression_list, expr);
 		if (!try_consume(c, TOKEN_COMMA))
 		{
-			CONSUME_OR_RET(TOKEN_RPAREN, false);
+			CONSUME_OR_RET(TOKEN_RPAREN, poisoned_expr);
 			break;
 		}
 	}

test/test_suite/compile_time/defined_parse_error.c3

@@ -0,0 +1,4 @@
+fn void main()
+{
+   $defined(usz a*); // #error: Expected ')'
+}