build error in finding root toml file.

[nathankg]

Hi! when trying to build a docker image, I'm running into this issue where when I run cargo cog build, the path to my root package is resolving incorrectly.

I have the following file structure:

matchmaker/ (workspace root)
  ├── Cargo.toml (root package)
  ├── src/ (root package source code)
  ├── matchmaker-js/ (child package)
  │     ├── Cargo.toml (child package's Cargo configuration)
  │     └── src/ (child package source code)
  └── test_utils/ (child package)
        ├── Cargo.toml (child package's Cargo configuration)
        └── src/ (child package source code)

And then I'm running the build command (RUST_BACKTRACE=1 cargo cog build -t matchmaker-service-image) in the matchmaker (root) directory.

My root toml file looks like below:

# matchmaker/Cargo.toml
[package]
edition = "2021"
name = "matchmaker"
version = "0.0.11"
authors = ["<...>"]

[package.metadata.cog]
image = "matchmaker-service-image" # optional, defaults to `cog-[package.name]`

[workspace]
members = [".", "server", "matchmaker-js", "test_utils"]
default-members = ["."]

[dependencies]
bytemuck = { version = "1.13.1", features = ["derive"] }
chef = "0.1.0"
cog-rust = "1.0.14"
env_logger = "0.10.0"
futures = "0.3.28"
futures-intrusive = "0.5.0"
handlebars = "4.3.7"
lazy_static = "1.4.0"
log = "0.4.19"
rayon = "1.7.0"
regex = "1.9.1"
serde_json = "1.0.103"
tokio = { version = "1.29.1", features = ["rt", "rt-multi-thread", "macros"] }
wgpu = "0.17.0"

[dev-dependencies]
criterion = { version = "0.5.1", features = ["async_tokio", "html_reports"] }
test_utils = { path = "./test_utils" }

[profile.release]
lto = true

[[bench]]
name="compatibility"
harness=false

[[bench]]
name="matching"
harness=false

Based on the error output, it seems like the matchmaker package is resolving to src/matchmaker/Cargo.toml instead of the intended src/Cargo.toml.

...
 => ERROR [builder 5/7] RUN cargo chef cook --release --bin matchmaker                                                                         0.7s
------
 > [builder 5/7] RUN cargo chef cook --release --bin matchmaker:
0.637 error: failed to load manifest for workspace member `/src/matchmaker`
0.637
0.637 Caused by:
0.637   failed to read `/src/matchmaker/Cargo.toml`
0.637
0.637 Caused by:
0.637   No such file or directory (os error 2)
0.639 thread 'main' panicked at 'Exited with status code: 101', /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/cargo-chef-0.1.62/src/recipe.rs:204:27
0.639 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
------
Dockerfile:12
--------------------
  10 |     RUN curl -L --proto '=https' --tlsv1.2 -sSf "https://github.com/cargo-bins/cargo-quickinstall/releases/download/cargo-deb-1.44.0/cargo-deb-1.44.0-x86_64-unknown-linux-gnu.tar.gz" | tar -xzvvf - -C /usr/local/cargo/bin
  11 |     COPY --from=planner /src/recipe.json recipe.json
  12 | >>> RUN cargo chef cook --release --bin matchmaker
  13 |     COPY . .
  14 |     RUN cargo deb --output /src/target/matchmaker.deb
--------------------
ERROR: failed to solve: process "/bin/sh -c cargo chef cook --release --bin matchmaker" did not complete successfully: exit code: 101
thread 'main' panicked at 'Failed to build docker image.', /home/ubuntu/.cargo/registry/src/index.crates.io-6f17d22bba15001f/cargo-cog-1.0.9/src/docker/builder.rs:239:9
...

I began to wonder if I'm referencing the root package wrong as a dependency, but even in my child packages, I refer to the matchmaker package as a dependency using the relative path: ".."

e.g.

# matchmaker/server/Cargo.toml
[package]
edition = "2021"
name = "matchmaker-server"
version = "0.0.1"
workspace = ".."

[dependencies]
matchmaker = { path = ".." }
tonic = "0.9.2"
prost = "0.11.9"
tokio = "1.29.1"

[build-dependencies]
tonic-build = "0.9.2"

New to rust and even newer to cog-rust, so very possible I missed specifying the appropriate key or field in the manifest. Any thoughts or help would be super appreciated :)