Cargo generate-lockfile picks dependencies that are too high for my current rustc

[zaporter]

Problem

If I delete my Cargo.lock and run cargo generate-lockfile, it picks clap_builder v4.5.2 which requires rustc 1.74 or newer. However, I am on 1.71 (and cannot upgrade yet due to toolchain reasons).

I have tried specifying rust-version = "1.71" in my Cargo.toml, however, that doesn't seem to have worked (I expect it would.)

It seems like cargo should only pick dependency versions that will actually compile on my version of rustc or should obey my rust-version

Steps

No response

Possible Solution(s)

If we don't want to auto-restrict to my version of rustc (or my rust-version in my cargo.toml), I think we could add an opt-in flag to restrict dependencies to a certain rustc version

Notes

No response

Version

cargo 1.71.0-nightly (cfd3bbd8f 2023-06-08)
release: 1.71.0-nightly
commit-hash: cfd3bbd8fe4fd92074dfad04b7eb9a923646839f
commit-date: 2023-06-08
host: x86_64-unknown-linux-gnu
libgit2: 1.6.4 (sys:0.17.1 vendored)
libcurl: 8.0.1-DEV (sys:0.4.61+curl-8.0.1 vendored ssl:OpenSSL/1.1.1t)
ssl: OpenSSL 1.1.1t  7 Feb 2023
os: Debian 12 (bookworm) [64-bit]

[weihanglo]

There is an unstable flag -Zmsrv-polocy for this, and it is still under development.

See also

• MSRV-dependent dependency version resolution #9930 for updates
• RFC: Make Cargo respect minimum supported Rust version (MSRV) when selecting dependencies rfcs#3537 for the recently merged RFC

Close in favour of aforementioned issues. Thanks for the report.