Enum MigrationError 

pub enum MigrationError {
    NotContiguous {
        position: usize,
        found: u32,
        expected: u32,
    },
    SchemaTooNew {
        current: u32,
        supported: u32,
    },
    Failed {
        version: u32,
        name: &'static str,
        source: Box<DbError>,
    },
    Ledger(Box<DbError>),
}

Why running the synced-schema ladder failed. Carried as its own arm of OpenError at the Database::open boundary — not flattened into a DbError string — so the variants stay typed for the engine’s own tests, the snapshot bootstrap gate, and hosts matching MigrationError::SchemaTooNew to prompt an app update.

Variants

NotContiguous

The registered set is not exactly 1..=N ascending with no gaps or duplicates — a host wiring bug, surfaced at startup before any DDL runs.

Fields

position: usize

found: u32

expected: u32

SchemaTooNew

The on-disk schema version is newer than this binary’s top migration, so this binary cannot apply a changeset (or open a snapshot image) at that version. Covers opening a snapshot written by a newer device and an older binary reopening a db a newer binary already migrated.

Fields

current: u32

supported: u32

Failed

A migration’s DDL or backfill failed. Its transaction rolled back, so user_version did not advance over the half-applied step.

Fields

version: u32

name: &'static str

source: Box<DbError>

Ledger(Box<DbError>)

Reading or writing user_version, or the BEGIN/COMMIT around a step, failed.

Trait Implementations

impl Debug for MigrationError

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

Formats the value using the given formatter.

impl Display for MigrationError

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

Formats the value using the given formatter.

impl Error for MigrationError

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.