error: cannot satisfy dependencies so `std` only shows up once

Question

This is an error I get when I try to run cargo test in a project. What does it mean? How do I fix it?

I can try to update with more details, but I could not reproduce it with a minimal example, unfortunately...

Full error:

cargo test
   Compiling ranges v0.1.0 (file:///Users/user/code/rust-project)
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 `rand` 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 `unwind` only shows up once
  |
  = help: having upstream crates all available in one format will likely make this go away

error: cannot satisfy dependencies so `panic_unwind` only shows up once
  |
  = help: having upstream crates all available in one format will likely make this go away

error: cannot link together two allocators: alloc_jemalloc and alloc_system

error: aborting due to 10 previous errors

It happens during the compilation step when I try to run tests that use the crate through an extern crate, like here: How do I access files in the src directory from files in my tests directory?

On OS X, rustc 1.12.0 (3191fbae9 2016-09-23)

Looks like https://github.com/rust-lang/rust/issues/19680, looks to me like a usability bug. — Matthieu M., Oct 28 '16 at 13:32
If that fixes it, should I let the q stand? Will check back after the weekend, gotta run :) — The Unfun Cat, Oct 28 '16 at 13:33
Certainly, a clear question on StackOverflow may be easier to find and a clear answer may be able to elaborate more. — Matthieu M., Oct 28 '16 at 13:34

score 16 · Accepted Answer · answered Nov 07 '16 at 14:25

16

Thanks to Matthieu M. for pointing me to the correct github issue!

The fix was to put the following in my Cargo.toml:

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

If you are using rustc the option

-C prefer-dynamic

should fix your problem.

answered Nov 07 '16 at 14:25

The Unfun Cat

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how to do this using cargo build in moden, 2022, rust? – realtebo Aug 17 '22 at 14:53
1

@realtebo `cargo rustc -- -C prefer-dynamic` still works today. – E_net4 Aug 17 '22 at 17:23
thanks! No available method to pass this flag when using `cargo build` ? – realtebo Aug 18 '22 at 07:40
1

@realtebo you can set it either via `RUSTFLAGS='-C prefer-dynamic' cargo build` or specifying it in `.cargo/config` - https://doc.rust-lang.org/cargo/reference/config.html – dbr Sep 11 '22 at 03:30

error: cannot satisfy dependencies so `std` only shows up once

1 Answers1