使用 Cargo 选择共享库或静态库

Question

我正在尝试修改 Racer 以发出共享库而不是 rlib。

为此，我将crate-type = ["dylib"] 添加到货物清单的[lib] 部分，然后运行cargo build --lib。这很好，libracer.so 被发出。

不幸的是，现在我无法构建 Racer 二进制文件，它依赖于库的静态版本。运行cargo build 抱怨：

   Compiling racer v1.0.0 (file:///home/georgev/dotfiles/vim/bundle/racer)
error: cannot satisfy dependencies so `std` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `core` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `collections` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `rustc_unicode` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `alloc` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `libc` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: cannot satisfy dependencies so `rand` only shows up once
help: having upstream crates all available in one format will likely make this go away
error: aborting due to 7 previous errors
Could not compile `racer`.

我把crate-type改成了["dylib", "bin"]，这样编译就成功了。但是，cargo build --lib 将不再发出共享库（只有 rlib）。

如何指定我想要构建的库类型，同时仍然允许静态构建所述库以包含在可执行文件中？

Answer 1

bin 不是有效的 crate-type 值。有效值为rlib、lib、staticlib 和dylib。将板条箱类型更改为

crate-type = ["dylib", "rlib"]

会导致你所追求的行为。

["dylib", "bin"] 仅发出 rlib 的原因是因为当前有一个 Cargo 错误导致 crate-type 的无效值仅生成 rlib。我已经提交了pull request 来解决这个问题。