I have the same problem of this post but cargo clean and cargo check doesn’t fix it.

This is my terminal output:

Updating crates.io index
error: failed to select a version for the requirement wasmtime = "^0.38.0"`
candidate versions found which didn't match: 0.37.0, 0.36.0, 0.35.3, ...
location searched: crates.io index
required by package sp-wasm-interface v6.0.0 (/substrate/primitives/wasm-interface)


rustup show output:

Default host: x86_64-apple-darwin
rustup home:  /Users/*****/.rustup

installed toolchains

stable-x86_64-apple-darwin (default)

active toolchain

stable-x86_64-apple-darwin (default)
rustc 1.59.0 (9d1b2106e 2022-02-23)
  • You must have given different version of the dependencies, just the versions and delete cargo.lock file and then build it. Commented Jul 6, 2022 at 9:39
  • I tried to delete cargo.lock but didn't work. I don't know I see wasmtime version 0.38.0 on creates.io
    – viac92
    Commented Jul 6, 2022 at 10:50
  • And cargo find it if I search with cargo search wasmtime first result wasmtime = "0.38.1 # High-level API to expose the Wasmtime runtime
    – viac92
    Commented Jul 6, 2022 at 10:59
  • You need to match all the dependencies version, it should be same. Your cargo is finding wasmtime = 0.38.1 but it needs a lower version of wasmtime. Commented Jul 6, 2022 at 11:27
  • Yes I know, in the Cargo.toml I have wasmtime = 0.38.0 but form the output of my terminal it seems cargo can't select this version. Is it correct? sorry I'm new with Rust
    – viac92
    Commented Jul 7, 2022 at 8:52

1 Answer 1


Update rust toolchain with command rustup update fixed the issue.

You could also try clean the registry index by remove folder ~/.cargo/registry/index if you don't want to update the toolchain.

  • It works, thank you!
    – viac92
    Commented Jul 11, 2022 at 7:44

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