Enum DaemonError 

pub enum DaemonError {
    Config {
        path: PathBuf,
        source: Error,
    },
    Io(Error),
    WorkspaceBuildFailed {
        root: PathBuf,
        reason: String,
    },
    WorkspaceStaleExpired {
        root: PathBuf,
        age_hours: u64,
        cap_hours: u32,
        last_good_at: Option<SystemTime>,
        last_error: Option<String>,
    },
    MemoryBudgetExceeded {
        limit_bytes: u64,
        current_bytes: u64,
        reserved_bytes: u64,
        retained_bytes: u64,
        requested_bytes: u64,
    },
    WorkspaceEvicted {
        root: PathBuf,
    },
    WorkspaceNotLoaded {
        root: PathBuf,
    },
    WorkspaceIncompatibleGraph {
        root: PathBuf,
        reason: String,
    },
    ToolTimeout {
        root: PathBuf,
        secs: u64,
        deadline_ms: u64,
    },
    InvalidArgument {
        reason: String,
    },
    RpcErrorPreserved(RpcError),
    Internal(Error),
    AlreadyRunning {
        socket: PathBuf,
        lock: PathBuf,
        owner_pid: Option<u32>,
    },
    AutoStartTimeout {
        timeout_secs: u64,
        socket: PathBuf,
    },
    SignalSetup {
        source: Error,
    },
    WorkspaceOversize {
        root: PathBuf,
        measured_bytes: u64,
        limit_bytes: u64,
        current_loaded_bytes: u64,
    },
    WorkspacePinned {
        root: PathBuf,
    },
    ResetWhileLoading {
        root: PathBuf,
    },
    ResetCancellationDispatched {
        root: PathBuf,
        retry_after_ms: u64,
    },
    SocketSetup {
        path: PathBuf,
        reason: String,
    },
    QueryTooBroad {
        reason: String,
        details: Value,
    },
}

All daemon-surface error variants.

Variants

Config

Config file could not be read or parsed.

Fields

path: PathBuf

source: Error

Io(Error)

An io::Error occurred outside the config surface (socket bind, pidfile lock, filesystem probe, etc.).

WorkspaceBuildFailed

Workspace load / rebuild failed with no prior-good graph to serve from.

Maps to JSON-RPC -32001.

Fields

root: PathBuf

reason: String

WorkspaceStaleExpired

Workspace is in the Failed state and the most recent successful build is older than the configured stale_serve_max_age_hours cap.

Maps to JSON-RPC -32002.

Fields

root: PathBuf

age_hours: u64

cap_hours: u32

last_good_at: Option<SystemTime>

Last successful build timestamp, if any. None when the workspace has never successfully built (edge case: should not reach WorkspaceStaleExpired in that case — WorkspaceBuildFailed is returned instead — but the type is permissive for future-proofing).

last_error: Option<String>

Textual diagnostic from the most recent failed build, if any.

MemoryBudgetExceeded

Admission control could not satisfy a reservation after evicting every non-pinned workspace.

Maps to JSON-RPC -32003.

Fields

limit_bytes: u64

current_bytes: u64

reserved_bytes: u64

retained_bytes: u64

requested_bytes: u64

WorkspaceEvicted

Workspace was evicted or removed between a rebuild dispatch and its admission / publish commit. Signals the Task 7b2 watcher task and any direct handle_changes caller to terminate their per-workspace loop — subsequent dispatches on the same WorkspaceKey must route through a fresh get_or_load first.

Surfaced by RebuildDispatcher::handle_changes’ top-of-drain-loop eviction gate AND by WorkspaceManager::reserve_rebuild’s Phase-1 workspaces.read() membership + cancellation check (both paths use this typed variant so 7b2 can match on it without string parsing).

Maps to JSON-RPC -32004.

Fields

root: PathBuf

WorkspaceNotLoaded

Caller requested daemon/rebuild or daemon/cancel_rebuild for a path that is not currently registered in the WorkspaceManager.

Shares the JSON-RPC -32004 code with Self::WorkspaceEvicted. The error_data "hint" field distinguishes the two situations on the wire.

Maps to JSON-RPC -32004.

Fields

root: PathBuf

WorkspaceIncompatibleGraph

On-disk graph snapshot or manifest is incompatible with this binary (unknown plugin ids in the manifest, or a snapshot format the runtime cannot parse). SGA02 / SGA04 mandate this stay distinct from Self::WorkspaceBuildFailed so clients can route “rebuild” vs. “upgrade binary” vs. “wait” responses correctly.

reason is a human-readable rendering of the underlying sqry_core::graph::acquisition::PluginSelectionStatus — the From<GraphAcquisitionError> impl below preserves the variant faithfully so no information is lost on the wire.

Maps to JSON-RPC -32005.

Fields

root: PathBuf

reason: String

ToolTimeout

Tool invocation exceeded DaemonConfig::tool_timeout_secs. Emitted by tool_core::classify_and_execute (Task 8 Phase 8c U6) when the tokio::time::timeout(tool_timeout, spawn_blocking(run)) outer timer fires. The detached tokio::task::JoinHandle is dropped — the OS thread may continue executing the tool closure but its result is discarded.

The deadline_ms field is the canonical wire value (populated by the constructor as secs * 1000) so error_data does not have to re-derive it on every call and serialised payloads remain byte-for-byte identical regardless of constructor shape.

Maps to JSON-RPC -32000.

Fields

root: PathBuf

secs: u64

deadline_ms: u64

Derived: secs * 1000. Stored explicitly to avoid re-calculating inside error_data / Display impls and to give the MCP-path wrapper (daemon_err_to_mcp, Phase 8c U8) a single field to read.

InvalidArgument

Argument validation failure surfaced by tool_core BEFORE any workspace classification runs. Used for resolve_index_root failures, missing path arguments in MCP tool args, and any other precondition violation that must be rejected with a JSON-RPC -32602 “Invalid params” response.

Maps to JSON-RPC -32602.

Fields

reason: String

RpcErrorPreserved(RpcError)

Typed sqry_mcp::error::RpcError preserved through the daemon-hosted MCP path so the wire envelope is byte-identical to the standalone MCP response (cluster-C iter-3, codex PR review recommendation).

The daemon adapter (sqry-mcp/src/daemon_adapter/dispatch.rs) previously rewrapped param-parsing failures with anyhow!("invalid arguments: {e}"), which destroyed the typed RpcError root before [crate::ipc::tool_core::execute_with_timeout] could downcast it. The downstream daemon_err_to_mcp then mapped through DaemonError::Internal → McpError::internal_error (-32603) regardless of the RpcError’s actual code. This variant is the dedicated pass-through: the inner RpcError carries the correct code (-32602 for validation failures, etc.), kind, retryable, retry_after_ms, and details, and daemon_err_to_mcp renders them through the same invalid_params / internal_error selector the standalone path uses.

Internal(Error)

Catch-all for errors surfaced by sqry_mcp::daemon_adapter tool execution that do not map to a more specific DaemonError variant. The wrapped anyhow::Error is flattened into a string on the wire via the Display/#[source] chain.

Maps to JSON-RPC -32603.

AlreadyRunning

A sqryd process already holds the exclusive flock on lock and has written its PID to pidfile. The caller should surface this to the user with the owner PID (if legible) and exit EX_TEMPFAIL (75).

This error fires before IpcServer::bind and therefore before any workspace is registered; it should never be stored in the workspace last_error field. [crate::workspace::manager::clone_err] maps it to WorkspaceBuildFailed as a defensive fallback.

Fields

socket: PathBuf

The IPC socket path that the running daemon owns.

lock: PathBuf

The flock file that proves ownership.

owner_pid: Option<u32>

PID of the owner process, if the pidfile was legible.

AutoStartTimeout

The daemon did not become ready within timeout_secs seconds. Used by both the --detach parent wait loop and the lifecycle::start_detached auto-spawn helper (Task 10).

Callers should exit EX_UNAVAILABLE (69).

Fields

timeout_secs: u64

How long we waited.

socket: PathBuf

The socket we polled.

SignalSetup

Installing OS signal handlers failed (e.g. sigaction returned ENOSYS in a highly-restricted container, or tokio’s signal registration failed).

Callers should exit EX_SOFTWARE (70).

Fields

source: Error

WorkspaceOversize

The freshly-built graph exceeds the daemon’s memory budget by itself — even if every other workspace were evicted, the daemon could not host it. Returned by WorkspaceManager::publish_and_retain AFTER the build completes but BEFORE the new graph is exposed to readers.

Wire code: -32006. Distinct from MemoryBudgetExceeded (-32003), which is a projected admission failure on a pre-build estimate.

Source: G_daemon_control_plane.md §1.4 hand-off G4.

Fields

root: PathBuf

measured_bytes: u64

limit_bytes: u64

current_loaded_bytes: u64

WorkspacePinned

daemon/reset was invoked on a pinned workspace and the caller did not pass force = true. Pinning is the operator opt-in for “do not LRU-evict this workspace”; resetting it has the same drop-graph effect as eviction and is therefore gated behind the same explicit override.

Wire code: -32010.

Source: G_daemon_control_plane.md §3.2 hand-off G4.

Fields

root: PathBuf

ResetWhileLoading

daemon/reset was invoked on a workspace whose state is Loading. Cancelling a load mid-flight is structurally unsafe (reservation accounting + admission state would drift). Caller must wait for the load to settle (success or Failed) and retry.

Wire code: -32008.

Source: G_daemon_control_plane.md §3.2 hand-off G4.

Fields

root: PathBuf

ResetCancellationDispatched

daemon/reset was invoked on a workspace whose state is Rebuilding. The reset has dispatched a cancellation token to the runner; the caller should retry after retry_after_ms for the runner to finish its drain pass and the workspace to transition to Failed (which is then idempotently reset on the next call).

Wire code: -32009.

Source: G_daemon_control_plane.md §3.2 hand-off G4.

Fields

root: PathBuf

retry_after_ms: u64

SocketSetup

Socket parent directory cannot be created or is not writable. Surfaced before IpcServer::bind so the failure mode is distinguishable from a generic EACCES (which would otherwise be wrapped as Io).

Wire code: -32007. Note this is not normally observed on the wire because it fires before the IPC server binds; the JSON-RPC mapping exists for the rare case where the daemon surface re-emits this through IPC during a hot-reload of the socket configuration.

Source: G_daemon_control_plane.md §5.2 hand-off G4.

Fields

path: PathBuf

reason: String

QueryTooBroad

Pre-flight cost gate rejected a query (per B_cost_gate.md §3, daemon-hosted MCP parity arm). The wire envelope mirrors the standalone RpcError::query_too_broad exactly so MCP clients can use a single parser regardless of which transport the request flowed through.

Wire code: -32602 (the existing invalid_params slot; kind = "query_too_broad" is the discriminator).

Source: B_cost_gate.md §3 + 00_contracts.md §3.CC-2.

Fields

reason: String

details: Value

Implementations

impl DaemonError

pub const fn jsonrpc_code(&self) -> Option<i32>

Map to the stable JSON-RPC error code used on the wire.

Returns None for errors that have no public JSON-RPC code — these are serialised as -32603 "Internal error" per the JSON-RPC 2.0 spec at the IPC boundary (wired in Task 8).

The Task 9 lifecycle variants (AlreadyRunning, AutoStartTimeout, SignalSetup) fire before IpcServer::bind so they never cross the IPC boundary directly; None is returned for them here. They are only surfaced to human users via exit_code() and process exit.

pub const fn exit_code(&self) -> u8

Map to a POSIX process exit code following the BSD sysexits.h conventions used for daemon CLI errors (Task 9 U1).

Code	Symbol	Semantics
0	EX_OK	Success (not an error; included for completeness)
69	EX_UNAVAILABLE	Service unavailable (timeout, not-ready)
70	EX_SOFTWARE	Internal software error
73	EX_CANTCREAT	IO error / cannot create required file
75	EX_TEMPFAIL	Try again (e.g. another instance is running)
78	EX_CONFIG	Configuration error

For variants that only occur inside the IPC / workspace layer (not at process-startup time) the JSON-RPC code’s sign-flipped magnitude is used as a proxy, falling back to 70 (EX_SOFTWARE) for anything not covered.

pub fn error_data(&self) -> Option<Value>

Build the error.data JSON payload surfaced alongside the JSON-RPC error code. Returns None when no structured payload should be attached (typically Io/Config errors routed through -32603).

Task 8 Phase 8a. The IPC method dispatch consumes this to populate JsonRpcError.data so clients can render actionable diagnostics without parsing the free-form message string.

Trait Implementations

impl Debug for DaemonError

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

Formats the value using the given formatter.

impl Display for DaemonError

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

Formats the value using the given formatter.

impl Error for DaemonError

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.

impl From<Error> for DaemonError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<GraphAcquisitionError> for DaemonError

fn from(err: GraphAcquisitionError) -> Self

Converts to this type from the input type.