CLI becomes permanently slow after enabling Docker Desktop integration

まず、Docker Desktop 統合を有効にした状態と無効にした状態で、docker --help と Tab 補完を使って WSL2 上の遅延を再現します。それらの状態での動作を比較し、CLI の起動および補完の経路を追跡してリグレッションを特定します。統合を無効にした後に両方のコマンドが速やかに戻り、この動作を対象とするリグレッションテストがあることを完了の条件とします。

Description

When Docker Desktop WSL2 integration is enabled on Windows, the CLI becomes noticeably slow. Even simple commands like docker --help take a few seconds to run, and tab-completion freezes for 3–4 seconds when attempting to complete a command. Turning off the integration does not resolve the problem.

Reproduce

1. Install Docker Engine on WSL2
2. Enable Docker Desktop WSL2 integration
3. Disable the integration

Expected behavior

Commands like docker --help and tab completion should run instantly instead of taking 3-5 seconds after disabling the integration.

docker version

Client: Docker Engine - Community
 Version:           28.4.0
 API version:       1.51
 Go version:        go1.24.7
 Git commit:        d8eb465
 Built:             Wed Sep  3 20:57:32 2025
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          28.4.0
  API version:      1.51 (minimum version 1.24)
  Go version:       go1.24.7
  Git commit:       249d679
  Built:            Wed Sep  3 20:57:32 2025
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.7.27
  GitCommit:        05044ec0a9a75232cad458027ca83437aae3f4da
 runc:
  Version:          1.2.5
  GitCommit:        v1.2.5-0-g59923ef
 docker-init:
  Version:          0.19.0
  GitCommit:        de40a

docker info

Client: Docker Engine - Community
 Version:    28.4.0
 Context:    default
 Debug Mode: false
 Plugins:
  ai: Docker AI Agent - Ask Gordon (Docker Inc.)
    Version:  v1.9.9
    Path:     /home/loczek/.docker/cli-plugins/docker-ai
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.27.0
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.39.2
    Path:     /usr/libexec/docker/cli-plugins/docker-compose
  scout: Docker Scout (Docker Inc.)
    Version:  v1.18.2
    Path:     /home/loczek/.docker/cli-plugins/docker-scout
WARNING: Plugin "/usr/local/lib/docker/cli-plugins/docker-dev" is not valid: failed to fetch metadata: fork/exec /usr/local/lib/docker/cli-plugins/docker-dev: no such file or directory
WARNING: Plugin "/usr/local/lib/docker/cli-plugins/docker-feedback" is not valid: failed to fetch metadata: fork/exec /usr/local/lib/docker/cli-plugins/docker-feedback: no such file or directory

Server:
 Containers: 31
  Running: 0
  Paused: 0
  Stopped: 31
 Images: 22
 Server Version: 28.4.0
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Swarm: inactive
 Runtimes: runc io.containerd.runc.v2
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 05044ec0a9a75232cad458027ca83437aae3f4da
 runc version: v1.2.5-0-g59923ef
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
 Kernel Version: 5.15.167.4-microsoft-standard-WSL2
 Operating System: Ubuntu 24.04.3 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 12
 Total Memory: 7.759GiB
 Name: DESKTOP-L
 ID: e99d46a4-4107-4c72-8ba0-926a91843451
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No blkio throttle.read_bps_device support
WARNING: No blkio throttle.write_bps_device support
WARNING: No blkio throttle.read_iops_device support
WARNING: No blkio throttle.write_iops_device support

Additional Info

No response