Build failure in vendor dir

[ggwpez]

Fails to build after doing a cargo vendor in one downstream repo, eg: https://github.com/polkadot-fellows/runtimes
I think its this line:

proc-macro-crate/src/lib.rs

Line 255 in c9671b5

Error::NotFound(manifest_path.to_owned())

Can it just use a mocked timestamp or something?

Example error from the repo above:

error: Could not find `Cargo.toml` in manifest dir: ``.
   --> runtimes/vendor/scale-info/src/ty/mod.rs:527:61
    |
527 | #[cfg_attr(any(feature = "std", feature = "decode"), derive(scale::Decode))]
    |                                                             ^^^^^^^^^^^^^
    |
    = note: this error originates in the derive macro `scale::Decode` (in Nightly builds, run with -Z macro-backtrace for more info)

[jplatte]

The error message suggests that CARGO_MANIFEST_DIR is set, but to an empty string. No idea why that would happen 🤷🏼

[jplatte]

Does it help to change

let manifest_dir = env::var("CARGO_MANIFEST_DIR").map_err(|_| Error::CargoManifestDirNotSet)?;

to

let mut manifest_dir = env::var("CARGO_MANIFEST_DIR").map_err(|_| Error::CargoManifestDirNotSet)?;
if manifest_dir.is_empty() {
    manifest_dir = ".".to_owned();
}

[ggwpez]

Thanks for the hint!
Maybe its something with the CWD, since the CARGO_MANIFEST_DIR is correctly set to the dependency dir, that also contains a Cargo.toml. i will try to see whats wrong.

[ggwpez]

I guess its one of the subsequent calls to to cargo_toml_timestamp and not the first one, since CARGO_MANIFEST_DIR looks good.