How to remove windows dependencies from Linux-only project

help
1

I have a fairly simple Cargo.toml for a project:

tokio = { version = "1", features = ["full"] }
warp = { version = "0.3", features = ["tls"] }
simplelog = "0.12.1"
log = "0.4.17"
serde = {version = "1.0", features = ["derive"]}
serde_json = "1.0"
confy = "0.5.1"
clap = { version = "4.2.7", features = ["derive", "cargo"] }
lazy_static = "1.4.0"
bytes = "1.4.0"
sysinfo = "0.29.0"
prost = "0.11"
# Only necessary if using Protobuf well-known types:
prost-types = "0.11"
serde_qs = "0.12.0"
anyhow = "1.0.71"
futures = "0.3.28"
derive-new = "0.5.9"
nix = { version = "0.26.2", default-features = false, features = ["signal"] }

I had to run cargo bitbake for something, and it printed many windows related dependencies:

    crate://crates.io/winapi-i686-pc-windows-gnu/0.4.0 \
    crate://crates.io/winapi-util/0.1.5 \
    crate://crates.io/winapi-x86_64-pc-windows-gnu/0.4.0 \
    crate://crates.io/winapi/0.3.9 \
    crate://crates.io/windows-sys/0.48.0 \
    crate://crates.io/windows-targets/0.48.0 \
    crate://crates.io/windows_aarch64_gnullvm/0.48.0 \
    crate://crates.io/windows_aarch64_msvc/0.48.0 \
    crate://crates.io/windows_i686_gnu/0.48.0 \
    crate://crates.io/windows_i686_msvc/0.48.0 \
    crate://crates.io/windows_x86_64_gnu/0.48.0 \
    crate://crates.io/windows_x86_64_gnullvm/0.48.0 \
    crate://crates.io/windows_x86_64_msvc/0.48.0 \

Does anyone know if there is a way to not include/remove these. They seem quite unnecessary (potentially increasing the binary size), if the project is only ever intended to be used on Linux.

2

If you are compiling on Linux, then Windows-specific code won't be included in the executable, for the simple reason that it can't be compiled on Linux. So if such a project successfully builds, then that means windows-only code has been #[cfg(…)]'d out.

6 Likes
3

False positive? Is the tool accurate for assessing such things?

Does "i686" appear in your Cargo.lock file? (It's a rhetorical question. @H2CO3 provided the answer to move forward.)

4

Such dependencies can and should be in a [target.'cfg(windows)'.dependencies] section which removes then from reverb being considered in a build, but so far as I can tell they are still fetched, most likely so lock file can be consistent across platforms.

3 Likes
5

Dependencies for other platforms are fetched when using cargo fetch or cargo vendor, but not when doing a regular build. The registry contains enough information to produce a valid lock file mentioning these dependencies without having to download the package tarballs.

2 Likes
6

This seems to be a bug in cargo bitcake which makes it include dependencies that would otherwise be disabled by cfg filters.

1 Like