Rust编译错误：Actix回退至不兼容的旧版本

我重启了一个一年半前的小型Rust项目——这是个用于管理书评、书籍引用及关联关系的简易API，也是我第一个Rust项目。更新依赖后执行cargo build时遇到编译错误，错误显示Actix相关旧版本代码与当前依赖不兼容。

具体编译错误 #

error[E0277]: cannot subtract `TimeDelta` from `Tm`
   --> C:\Users\zerok\.cargo\registry\src\index.crates.io-6f17d22bba15001f\actix-http-1.0.1\src\cookie\jar.rs:224:44
    |
224 |             cookie.set_expires(time::now() - Duration::days(365));
    |                                            ^ no implementation for `Tm - TimeDelta`
    |
    = help: the trait `Sub<TimeDelta>` is not implemented for `Tm`
    = help: the following other types implement trait `Sub<Rhs>`:
              `Tm` implements `Sub<time::Duration>`
              `Tm` implements `Sub`

error[E0308]: mismatched types
   --> C:\Users\zerok\.cargo\registry\src\index.crates.io-6f17d22bba15001f\actix-http-1.0.1\src\cookie\mod.rs:736:40
    |
736 |         self.set_expires(time::now() + twenty_years);
    |                                        ^^^^^^^^^^^^ expected `Duration`, found `TimeDelta`

项目的Cargo.toml内容 #

[package]
name = "rust_web_server"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
diesel = { version = "2.0.3", features = ["sqlite", "r2d2", "returning_clauses_for_sqlite_3_35"] }
dotenvy = "0.15"
actix-web = "4"
actix-web-httpauth = { git = "https://github.com/actix/actix-web-httpauth" }
chrono = { version = "0.4.10", features = ["serde"] }
derive_more = "0.99.2"
futures = "0.3.1"
r2d2 = "0.8.8"
serde = "1.0"
serde_derive = "1.0"
serde_json = "1.0"
alcoholic_jwt = "1.0.0"
reqwest = "0.9.22"
actix-rt = "2.7.0"
dotenv = "0.15.0"
tokio-test = "0.4.2"
actix-service = { version = "2.0.2" }

[dependencies.uuid]
version = "1.3.0"
features = [
    "v4",
    "fast-rng"
]

问题根源与解决步骤 #

问题根源 #

错误来自actix-http 1.0.1这个老旧版本，而你指定了actix-web = "4"（正常应依赖actix-http 3.x）。导致版本回退的核心原因是依赖冲突：

• actix-web-httpauth使用git仓库直接拉取的方式，其依赖配置未正确适配actix-web 4，触发cargo自动选择兼容的旧版actix-http。
• reqwest = "0.9.22"版本过旧，它的依赖链可能引入过时包，间接干扰actix系列依赖的版本选择。

解决步骤 #

1. 替换actix-web-httpauth为稳定适配版
   去掉git依赖，改用官方适配actix-web 4的稳定版本：

   actix-web-httpauth = "0.8"
   

2. 更新reqwest到兼容版本
   将过时的reqwest 0.9替换为适配当前生态的版本：

   reqwest = "0.11"
   

   注意：版本升级后可能需要调整代码中reqwest的调用逻辑，因为跨大版本API有变化。

3. 固定actix-http版本
   在Cargo.toml中明确指定actix-http版本，强制与actix-web 4匹配：

   actix-http = "3"
   

4. 清理并重新构建
   执行命令清理旧依赖缓存，重新拉取并构建：

   cargo clean
   cargo update
   cargo build
   

内容的提问来源于stack exchange，提问作者Zerok