deepseek-ai/deepseek-harness · error · WorkspaceMoveInvalidError

cannot move session '${sessionId}' before '${beforeSessionId

Error message

cannot move session '${sessionId}' before '${beforeSessionId}' in workspace '${record.path}': the anchor session is not accounted

What it means

Error "cannot move session '${sessionId}' before '${beforeSessionId}' in workspace '${record.path}': the anchor session is not accounted" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/workspace/workspace/src/entity.ts:159

          + `its cwd resolves to '${cwd}'`,
        )
      }
      this.host.rememberSessionPath(sessionId, cwd)
    }
    await this.mutate(record => record.sessionIds.includes(sessionId)
      ? record
      : { ...record, sessionIds: [sessionId, ...record.sessionIds] })
  }

  async insertSessionBefore(sessionId: SessionId, beforeSessionId?: SessionId): Promise<void> {
    await this.mutate((record) => {
      if (!record.sessionIds.includes(sessionId)) {
        throw new WorkspaceMoveInvalidError(
          `cannot move session '${sessionId}' in workspace '${record.path}': the session is not accounted`,
        )
      }
      if (beforeSessionId !== undefined && !record.sessionIds.includes(beforeSessionId)) {
        throw new WorkspaceMoveInvalidError(
          `cannot move session '${sessionId}' before '${beforeSessionId}' in workspace '${record.path}': `
          + 'the anchor session is not accounted',
        )
      }
      if (beforeSessionId === sessionId) return record
      const without = record.sessionIds.filter(id => id !== sessionId)
      const at = beforeSessionId === undefined ? without.length : without.indexOf(beforeSessionId)
      const sessionIds = [...without.slice(0, at), sessionId, ...without.slice(at)]
      return sessionIds.every((id, index) => id === record.sessionIds[index])
        ? record
        : { ...record, sessionIds }
    })
  }

  async detachSession(sessionId: SessionId): Promise<void> {
    await this.mutate(record => record.sessionIds.includes(sessionId)
      ? { ...record, sessionIds: record.sessionIds.filter(id => id !== sessionId) }
      : record)

View on GitHub (pinned to b150a551b8)

Solutions

1. Pick an anchor session that is accounted by the workspace, or attach the anchor session first.

When it happens

Trigger: Thrown at packages/workspace/workspace/src/entity.ts:159 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/a5c1f514c5f0836d. Report an issue: GitHub.