commenting out feature flag does not affect recompilation

[tspiteri]

First I compile this code with cargo +nightly build:

#![feature(nll)]
pub fn foo() {
    let mut v = vec![1];
    v.push(v[0]);
}

Then I comment out the feature flag:

//#![feature(nll)]
pub fn foo() {
    let mut v = vec![1];
    v.push(v[0]);
}

Then I recompile and it does not fail, even though the code currently requires the feature flag to compile. I guess incremental recompilation is not detecting the change.

If I cargo clean before recompiling, or if I completely delete the line (thus changing line numbers for the following lines), the recompilation fails as it should.

[michaelwoerister]

Interesting. Thanks for the bug report, @tspiteri!