Enum LockError 

pub enum LockError {
    Held {
        kind: LockKind,
        path: PathBuf,
        holder: Option<Box<LockHolder>>,
        refused_with: Option<i32>,
    },
    Io {
        path: PathBuf,
        source: Error,
    },
    Identity {
        kind: LockKind,
        source: ProcessError,
    },
}

Something went wrong taking or inspecting a lock.

Variants

Held

Somebody else has it.

Fields

kind: LockKind

Which lock.

path: PathBuf

Where the lock file is, so the message is actionable on a host with a non-default layout.

holder: Option<Box<LockHolder>>

Who holds it, when the record could be read. None is not the same as “nobody”: it means the holder had not finished identifying itself, which is a race of microseconds and not a reason to proceed.

Boxed because this variant travels inside a Result that e1 carries across a spawn_blocking boundary, and an inline LockHolder makes that Err large enough for clippy’s result_large_err to refuse the build. The indirection costs one allocation on a path that has already lost a lock race.

refused_with: Option<i32>

The operating system code the refusal actually carried.

Why an errno is in a user-facing message

This variant has two causes that look identical once it is constructed: the lock is genuinely somebody else’s, or the operating system said “would block” for a reason this code does not model. The second is not hypothetical — a refusal that no reading of this module explains has been seen in CI on both Unix platforms, for a lock the same process had just released, and there was nothing in the message to tell the two apart.

Carrying the raw code costs a few characters and turns the next occurrence from a mystery into a report. None where the platform excluded at the open rather than at the lock call.

Io

The lock file could not be opened, read, or written.

Fields

path: PathBuf

The lock file.

source: Error

The underlying error.

Identity

The holder’s own identity could not be read, so it could not record who it is.

Fields

kind: LockKind

Which lock.

source: ProcessError

The underlying error.

Trait Implementations

impl Debug for LockError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for LockError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for LockError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.