rust - 错误 : the `?` operator is not stable error when installing cargo-update

Question

我正在尝试更新 cargo:cargo install cargo-update，但我遇到了以下错误:

   Compiling semver-parser v0.7.0
error: the `?` operator is not stable (see issue #31436)
  --> /home/netlab/.cargo/registry/src/github.com-1ecc6299db9ec823/semver-parser-0.7.0/src/version.rs:56:26
   |
56 |     let (pre, pre_len) = common::parse_optional_meta(&s[i..], b'-')?;
   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: the `?` operator is not stable (see issue #31436)
  --> /home/netlab/.cargo/registry/src/github.com-1ecc6299db9ec823/semver-parser-0.7.0/src/version.rs:58:30
   |
58 |     let (build, build_len) = common::parse_optional_meta(&s[i..], b'+')?;
   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: the `?` operator is not stable (see issue #31436)
   --> /home/netlab/.cargo/registry/src/github.com-1ecc6299db9ec823/semver-parser-0.7.0/src/range.rs:133:26
    |
133 |     let (pre, pre_len) = common::parse_optional_meta(&s[i..], b'-')?;
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Answer 1

这取决于您的 Rust 版本 — versions of Rust before 1.13您将收到错误消息，因为运算符在这些版本中不稳定。

您的错误消息指的是 a GitHub issue number .