Code compiles on playground but fails when passed via stdin to rustc

I've run into the following very strange behaviour and am unsure whether it's some kind of weird bug that I should report or a subtle mistake on my part.

The following code compiles and runs fine on playground (as does an equivalent test locally)

#![allow(stable_features)]
#![allow(unused)]
#![feature(iterator_try_collect)]
fn main() {
    let foo: Option<Vec<_>> = [Some(1)].into_iter().try_collect();
    assert_eq!(foo.unwrap().len(), 1);
}

but when passed via stdin to rustc --crate-name flurb --crate-type=lib --out-dir target/flurb --emit=llvm-ir - it fails with

error[E0277]: the trait bound `&Option<{integer}>: Try` is not satisfied
    --> <anon>:5:53
     |
   5 |     let foo: Option<Vec<_>> = [Some(1)].into_iter().try_collect();
     |                                                     ^^^^^^^^^^^ the nightly-only, unstable trait `Try` is not implemented for `&Option<{integer}>`
     |
help: the trait `Try` is implemented for `Option<T>`
    --> /opt/rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:2767:1
     |
2767 | impl<T> const ops::Try for Option<T> {
     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0277`.

Is there a reason for the difference in output from a direct rustc invocation vs a cargo/playground based compilation?