Build error on fresh install

[nk9]

I created a fresh lambda, but can't get it to build.

$ brew tap cargo-lambda/cargo-lambda && brew install cargo-lambda
...
$ brew list cargo-lambda
/opt/homebrew/Cellar/cargo-lambda/1.6.3.aarch64/bin/cargo-lambda
/opt/homebrew/Cellar/cargo-lambda/1.6.3.aarch64/sbom.spdx.json
$ cargo lambda new islington-events
> Is this function an HTTP function? Yes
$ cd islington-events
$ cargo lambda build
▪▪▪▪▪ Target component installed
   Compiling proc-macro2 v1.0.93
   Compiling unicode-ident v1.0.16
   Compiling serde v1.0.217
   Compiling pin-project-lite v0.2.16
   Compiling itoa v1.0.14
   Compiling futures-core v0.3.31
   Compiling stable_deref_trait v1.2.0
   Compiling memchr v2.7.4
   Compiling autocfg v1.4.0
   Compiling futures-sink v0.3.31
error[E0463]: can't find crate for `core`
  |
  = note: the `x86_64-unknown-linux-gnu` target may not be installed
  = help: consider downloading the target with `rustup target add x86_64-unknown-linux-gnu`

For more information about this error, try `rustc --explain E0463`.
error: could not compile `futures-core` (lib) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: could not compile `pin-project-lite` (lib) due to 1 previous error
error: could not compile `itoa` (lib) due to 1 previous error
error: could not compile `stable_deref_trait` (lib) due to 1 previous error
error: could not compile `futures-sink` (lib) due to 1 previous error
error: could not compile `memchr` (lib) due to 1 previous error
$ rustup target add x86_64-unknown-linux-gnu
info: component 'rust-std' for target 'x86_64-unknown-linux-gnu' is up to date

Version info:

$ cargo lambda --version
cargo-lambda 1.6.3 (7b294c9 2025-01-27Z)
$ system_profiler SPSoftwareDataType
Software:

    System Software Overview:

      System Version: macOS 15.2 (24C101)
      Kernel Version: Darwin 24.2.0
$ uname -p
arm
$ rustc --version
rustc 1.84.1 (e71f9a9a9 2025-01-27) (Homebrew)
$ cargo --version
cargo 1.84.1

[nk9]

I have gotten this working locally by using cargo lambda watch, but build and build --release still generate the same error. 🤔

[calavera]

error[E0463]: can't find crate for core

This error is always caused because the Rust toolchain is not correctly installed. I’d recommend you to remove the toolchain with rustup and install it again. You can see dozens of similar problems in different Rust projects:

https://github.com/search?q=%22can%27t+find+crate+for+%60core%60%22&type=issues

[nk9]

Thank you very much! I tried uninstalling individual toolchains to start, but that didn't help. Then I found this StackOverflow answer that recommended deleting rust entirely and starting from scratch. And now the build works!

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