Platform bin spec must be in format 'platform:path', got

Error message

Platform bin spec must be in format 'platform:path', got: {}

What it means

This error is thrown by `parse_platform_bin_spec` when a `--platform-bin` argument does not contain a ':'-separated 'platform:path' pair. The spec is split once on ':' and must yield exactly two parts: the platform name and the path to the binary inside the archive. It validates user-provided binary location overrides before archive analysis.

Solutions

Change the value to include the platform prefix: --platform-bin linux:bin/tool
Check that you are using --platform-bin (requires platform:path) and not --bin (path only)
Quote the argument so platform and path remain one shell word: --platform-bin "macos-x64:bin/tool"

Example fix

// before
--platform-bin bin/tool
// after
--platform-bin linux:bin/tool

Defensive patterns

Strategy: validation

Validate before calling

validate_platform_bin() {
  local spec="$1"
  case "$spec" in
    *:*) return 0 ;;
    *) echo "--platform-bin must be 'platform:path'" >&2; return 1 ;;
  esac
}
validate_platform_bin "$SPEC" || exit 1

Prevention

Remember --platform-bin needs the platform prefix; use --bin for a path-only override
Quote arguments containing colons
Verify archive-relative binary paths with tar -tf before generating the stub

When it happens

Trigger: Running `mise generate tool-stub` with `--platform-bin` set to a value without a colon, e.g. --platform-bin bin/tool (missing the platform prefix) or --platform-bin linux (path omitted).

Common situations: Users copying the --bin flag syntax (which takes only a path) instead of --platform-bin; Windows-style absolute paths like C:\bin\tool confusing the author about separator placement; forgetting the platform prefix when specifying per-platform binaries.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/0e597a0394563024. Report an issue: GitHub.

Appendix: source

Thrown at src/cli/generate/tool_stub.rs:553

            // Format: platform:url
            let parts: Vec<&str> = spec.splitn(2, ':').collect();
            if parts.len() != 2 {
                bail!(
                    "Platform spec must be in format 'platform:url' or just 'url' (for auto-detection). Got: {}",
                    spec
                );
            }

            let platform = parts[0].to_string();
            let url = parts[1].to_string();
            Ok((platform, url))
        }
    }

    fn parse_platform_bin_spec(&self, spec: &str) -> Result<(String, String)> {
        let parts: Vec<&str> = spec.splitn(2, ':').collect();
        if parts.len() != 2 {
            bail!(
                "Platform bin spec must be in format 'platform:path', got: {}",
                spec
            );
        }

        let platform = parts[0].to_string();
        let bin_path = parts[1].to_string();

        Ok((platform, bin_path))
    }

    async fn analyze_url(
        &self,
        url: &str,
        mpr: &std::sync::Arc<crate::ui::multi_progress_report::MultiProgressReport>,
    ) -> Result<(String, u64, Option<String>)> {
        // Create a temporary directory for download and extraction
        let temp_dir = tempfile::tempdir()?;

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