deepseek-ai/deepseek-harness · error

workspace-attach-failed

workspace-attach-failed

Error message

session "${sessionId}" was created but could not attach to workspace "${workspace.id}": ${String(error)}

What it means

Error "session "${sessionId}" was created but could not attach to workspace "${workspace.id}": ${String(error)}" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/host/apiproxy/src/api-proxy.ts:2134

                requestedCwd: error.requestedCwd,
                ...error.existingCwd === undefined ? {} : { existingCwd: error.existingCwd },
              },
            })
          }
          if (error instanceof SubagentSessionOwnership) {
            return err(request, subagentOwnershipError(error.sessionId))
          }
          return err(request, {
            code: 'internal',
            message: `failed to create session "${sessionId}": ${String(error)}`,
            details: {},
          })
        }
        if (workspace !== undefined) {
          try {
            await workspace.attachSession(sessionId)
          } catch (error: unknown) {
            return err(request, {
              code: 'workspace-attach-failed',
              message: `session "${sessionId}" was created but could not attach to workspace "${workspace.id}": ${String(error)}`,
              details: { sessionId, workspaceId: workspace.id },
            })
          }
        }
        // Echo the composition the session RUNS so a client can label it
        // without waiting for the next list refresh — the create is the commit
        // point that knows it (a caller that named none gets the default).
        // Resolved from the log for the same reason `sessionListFields()` is:
        // this handler also adopts an already-live session, and one that
        // switched while blank runs a preset its header no longer names, so
        // echoing the header would contradict both the adoption this call just
        // allowed and the row `session.list` serves for the same session.
        const created = ctx.agents.get(sessionId)
        const createdPreset = created === undefined ? undefined : resolveSessionPreset(created.session)
        return ok(request, { sessionId, ...createdPreset === undefined ? {} : { agentPreset: createdPreset } })
      },

View on GitHub (pinned to b150a551b8)

Solutions

1. Fix the session/workspace attach failure named in the embedded error (cwd outside workspace, missing header), then attach or recreate the session.

When it happens

Trigger: Thrown at packages/host/apiproxy/src/api-proxy.ts:2134 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/28fef78b547ce264. Report an issue: GitHub.