如何覆盖 Cargo 配置目录的位置？
How can the location of Cargo's configuration directory be overridden?
Cargo 在搜索其配置目录时的默认行为似乎是在当前用户的主目录中查找（~/.cargo 在我的系统上）。如何修改此行为以使 Cargo 在用户提供的目录中查找？
可以通过环境变量 $CARGO_HOME 更改默认位置，它会覆盖默认位置 $HOME/.cargo。
Environment variables Cargo reads
You can override these environment variables to change Cargo's
behavior on your system:
CARGO_HOME — Cargo maintains a local cache of the registry index and of git checkouts of crates. By default these are stored under
$HOME/.cargo, but this variable overrides the location of this
directory. Once a crate is cached it is not removed by the clean
command.CARGO_TARGET_DIR — Location of where to place all generated artifacts, relative to the current working directory.RUSTC — Instead of running rustc, Cargo will execute this specified compiler instead.RUSTC_WRAPPER — Instead of simply running rustc, Cargo will execute this specified wrapper instead, passing as its commandline
arguments the rustc invocation, with the first argument being rustc.RUSTDOC — Instead of running rustdoc, Cargo will execute this specified rustdoc instance instead.RUSTDOCFLAGS — A space-separated list of custom flags to pass to all rustdoc invocations that Cargo performs. In contrast with
cargo rustdoc, this is useful for passing a flag to all
rustdoc instances.RUSTFLAGS — A space-separated list of custom flags to pass to all compiler invocations that Cargo performs. In contrast with cargo rustc,
this is useful for passing a flag to all compiler
instances.CARGO_INCREMENTAL — If this is set to 1 then Cargo will force incremental compilation to be enabled for the current compilation,
and when set to 0 it will force disabling it. If this env var isn't
present then cargo's defaults will otherwise be used.CARGO_CACHE_RUSTC_INFO — If this is set to 0 then Cargo will not try to cache compiler version information.
Hierarchical structure
Cargo allows local configuration for a particular package as well as
global configuration, like git. Cargo extends this to a hierarchical
strategy. If, for example, Cargo were invoked in
/projects/foo/bar/baz, then the following configuration files would
be probed for and unified in this order:
/projects/foo/bar/baz/.cargo/config/projects/foo/bar/.cargo/config/projects/foo/.cargo/config/projects/.cargo/config/.cargo/config$HOME/.cargo/config
With this structure, you can specify configuration per-package, and
even possibly check it into version control. You can also specify
personal defaults with a configuration file in your home directory.
Cargo 在搜索其配置目录时的默认行为似乎是在当前用户的主目录中查找（~/.cargo 在我的系统上）。如何修改此行为以使 Cargo 在用户提供的目录中查找？
可以通过环境变量 $CARGO_HOME 更改默认位置，它会覆盖默认位置 $HOME/.cargo。
Environment variables Cargo reads
You can override these environment variables to change Cargo's behavior on your system:
CARGO_HOME— Cargo maintains a local cache of the registry index and of git checkouts of crates. By default these are stored under$HOME/.cargo, but this variable overrides the location of this directory. Once a crate is cached it is not removed by the clean command.CARGO_TARGET_DIR— Location of where to place all generated artifacts, relative to the current working directory.RUSTC— Instead of runningrustc, Cargo will execute this specified compiler instead.RUSTC_WRAPPER— Instead of simply runningrustc, Cargo will execute this specified wrapper instead, passing as its commandline arguments the rustc invocation, with the first argument being rustc.RUSTDOC— Instead of runningrustdoc, Cargo will execute this specifiedrustdocinstance instead.RUSTDOCFLAGS— A space-separated list of custom flags to pass to allrustdocinvocations that Cargo performs. In contrast withcargo rustdoc, this is useful for passing a flag to allrustdocinstances.RUSTFLAGS— A space-separated list of custom flags to pass to all compiler invocations that Cargo performs. In contrast withcargo rustc, this is useful for passing a flag to all compiler instances.CARGO_INCREMENTAL— If this is set to 1 then Cargo will force incremental compilation to be enabled for the current compilation, and when set to 0 it will force disabling it. If this env var isn't present then cargo's defaults will otherwise be used.CARGO_CACHE_RUSTC_INFO— If this is set to 0 then Cargo will not try to cache compiler version information.
Hierarchical structure
Cargo allows local configuration for a particular package as well as global configuration, like git. Cargo extends this to a hierarchical strategy. If, for example, Cargo were invoked in
/projects/foo/bar/baz, then the following configuration files would be probed for and unified in this order:
/projects/foo/bar/baz/.cargo/config/projects/foo/bar/.cargo/config/projects/foo/.cargo/config/projects/.cargo/config/.cargo/config$HOME/.cargo/configWith this structure, you can specify configuration per-package, and even possibly check it into version control. You can also specify personal defaults with a configuration file in your home directory.