could not find ` ` in ` ` or any parent directory, but…

Error message

could not find `{}` in `{}` or any parent directory, but found cargo.toml please try to rename it to Cargo.toml

What it means

find_root_manifest_for_wd walks ancestors of cwd looking for Cargo.toml. If it never finds the correctly-cased file but does encounter a lowercase cargo.toml somewhere up the tree, it reports the case mismatch — a common failure on case-sensitive filesystems.

Solutions

Rename the file to Cargo.toml: `git mv cargo.toml Cargo.toml` (or plain mv if untracked).
On case-insensitive filesystems use `git mv -f` with a two-step rename to force the case change in git.
Verify with `ls -la | grep -i cargo.toml` that the correct case is present.

Example fix

# before
# ls
# cargo.toml

# after
# git mv cargo.toml Cargo.toml
# git commit -m "Fix manifest filename casing"

Defensive patterns

Strategy: validation

Validate before calling

use std::path::Path;

fn find_correctly_cased_manifest(cwd: &Path) -> Result<PathBuf, String> {
    for dir in paths::ancestors(cwd, None) {
        let p = dir.join("Cargo.toml");
        if p.is_file() { return Ok(p); }
        if dir.join("cargo.toml").is_file() {
            return Err(format!("found lowercase cargo.toml at {}; rename to Cargo.toml", dir.display()));
        }
    }
    Err("no Cargo.toml found".into())
}

Type guard

fn manifest_case_is_correct(dir: &std::path::Path) -> bool {
    dir.join("Cargo.toml").is_file()
}

Prevention

On case-sensitive filesystems, always create the manifest as `Cargo.toml` (capital C, capital T).
Add a CI lint that fails if any `cargo.toml` (lowercase) appears in the repo.
After cloning on Linux, run `git ls-files | grep -i 'cargo.toml'` to spot mis-cased manifests.

When it happens

Trigger: Running any cargo command from inside a directory tree where the manifest was created as `cargo.toml` (lowercase) on a case-sensitive filesystem (Linux default).

Common situations: File created on macOS/Windows and committed with wrong case; editor autocorrect lowercased the filename; clone on Linux of a repo with a misnamed manifest.

Related errors

AI-assisted analysis of rust-lang/cargo@eb98b54bc9 (2026-08-11). Data as JSON: /api/errors/cae0bde5bbcde376. Report an issue: GitHub.

Appendix: source

Thrown at src/util/important_paths.rs:22

/// Finds the root `Cargo.toml`.
pub fn find_root_manifest_for_wd(cwd: &Path) -> CargoResult<PathBuf> {
    let valid_cargo_toml_file_name = "Cargo.toml";
    let invalid_cargo_toml_file_name = "cargo.toml";
    let mut invalid_cargo_toml_path_exists = false;

    for current in paths::ancestors(cwd, None) {
        let manifest = current.join(valid_cargo_toml_file_name);
        if manifest.exists() {
            return Ok(manifest);
        }
        if current.join(invalid_cargo_toml_file_name).exists() {
            invalid_cargo_toml_path_exists = true;
        }
    }

    if invalid_cargo_toml_path_exists {
        anyhow::bail!(
            "could not find `{}` in `{}` or any parent directory, but found cargo.toml please try to rename it to Cargo.toml",
            valid_cargo_toml_file_name,
            cwd.display()
        )
    } else {
        anyhow::bail!(
            "could not find `{}` in `{}` or any parent directory",
            valid_cargo_toml_file_name,
            cwd.display()
        )
    }
}

/// Returns the path to the `file` in `pwd`, if it exists.
pub fn find_project_manifest_exact(pwd: &Path, file: &str) -> CargoResult<PathBuf> {
    let manifest = pwd.join(file);

    if manifest.exists() {

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