`npx sls package` fails in CircleCI Linux container

[Max Countryman]

I seem to be running into an issue when I try to execute the package command within a CircleCI job using the Docker image circleci/rust:latest-node:

$ npx sls package
Serverless: Building native Rust myfunction func...
error: could not find `Cargo.toml` in `/code` or any parent directory
Serverless: Dockerized Rust build encountered an error: undefined 1.

  Error --------------------------------------------------


     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.

  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Issues:        forum.serverless.com

  Your Environment Information ---------------------------
     Operating System:          linux
     Node Version:              10.16.1
     Serverless Version:        1.49.0
     Enterprise Plugin Version: 1.3.8
     Platform SDK Version:      2.1.0

Listing the directory in fact reveals the expected Cargo.toml so the error seems a bit misleading:

$ ls
Cargo.lock  Cargo.toml  README.md  myfunction  myotherfunctiuon  node_modules  package-lock.json  package.json  serverless.yml  target

Any help is appreciated.

[Max Countryman]

It seems this is already being tracked here: softprops/serverless-rust#40