I looked around but it seems printpdf or lopdf also using syn's old version and it require stdweb.
https://github.com/rustwasm/wasm-bindgen/issues/3415 It is because syn using stdweb, so i have to fix it with update wasm-bindgen and syn.
I have no idea why stdweb there but i am using genpdf with my wasm project. It worked well until today. I cleaned my project with cargo clean and it started failing. everything compiles fine except stdweb.