Missing package in Cargo.lock while it's present in Cargo.toml

[niebayes]

Does cargo guarantee each items in Cargo.toml would be present in Cargo.lock?
I have introduced a package bytes (version 1.8.0) in Cargo.toml, but the Cargo.lock file only has a bytes package of version 1.9.0.
Is this an expected behavior of cargo?

[epage]

Providing reproduction steps would be a big help to take the guess work out of answering your question.

I'm going to assume you have bytes = "1.8". That is a version requirement, one that specifies the minimum semver-compatible version to use. In recent versions of cargo, when it adds bytes to your lockfile, you'll see a message Locking latest compatible versions.

For more, see https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#version-requirement-syntax

[niebayes]

@epage Thanks! I was thinking the version declared in Cargo.toml is the strict requirement that must be fulfilled, which is to say the actual used version is exactly the version declared in Cargo.toml. But it's not the case.