https://github.com/rust-lang/rust/pull/102935 changed the behaviour of format!("{:.0}", 0.5) to round to 0 instead of 1 for consistency. The test case I copied from std was using this, so change to using 1.5 which has the same behaviour on stable and nightly.
Nemo157
commented
2 years ago 
bors[bot]
https://github.com/rust-lang/rust/pull/102935 changed the behaviour of
format!("{:.0}", 0.5)to round to 0 instead of 1 for consistency. The test case I copied fromstdwas using this, so change to using 1.5 which has the same behaviour on stable and nightly.