try to resolve under eager expander

compiler/rustc_builtin_macros/src/format.rs

@@ -39,6 +39,7 @@ use PositionUsedAs::*;
 
 use crate::errors;
 
+#[derive(Debug)]
 struct MacroInput {
     fmtstr: P<Expr>,
     args: FormatArguments,

compiler/rustc_expand/src/expand.rs

@@ -549,9 +549,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     }
 
     fn resolve_imports(&mut self) {
-        if self.monotonic {
-            self.cx.resolver.resolve_imports();
-        }
+        self.cx.resolver.resolve_imports();
     }
 
     /// Collects all macro invocations reachable at this time in this AST fragment, and replace

tests/ui/macros/expand-full-in-format-str.rs

@@ -0,0 +1,22 @@
+//@check-pass
+//@edition: 2018
+
+// https://github.com/rust-lang/rust/issues/98291
+
+macro_rules! wrap {
+    () => {
+        macro_rules! _a {
+            () => {
+                "Hello world"
+            };
+        }
+    };
+}
+
+wrap!();
+
+use _a as a;
+
+fn main() {
+    format_args!(a!());
+}