Debugger does not pause when copying a non-existent file #3437
Description
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I've found a bug and checked that ...
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Description
When trying to debug a Dockerfile build that uses COPY on something that does not exist in the build context, the debug session is terminated instead of pausing. In comparison, if I do RUN cat non-existent-file.txt the debugger does pause so I would have expected the COPY call to also suspend the debug session instead of simply terminating.
Expected behaviour
The debug session should suspend instead of terminating.
Actual behaviour
The debug session terminates.
Buildx version
github.com/docker/buildx v0.29.0-rc1-2-gb4b698c0 b4b698c
Docker info
Client:
Version: 28.4.0
Context: desktop-linux
Debug Mode: false
Plugins:
ai: Docker AI Agent - Ask Gordon (Docker Inc.)
Version: v1.9.11
Path: /Users/rcjsuen/.docker/cli-plugins/docker-ai
buildx: Docker Buildx (Docker Inc.)
Version: v0.29.0-rc1-2-gb4b698c0
Path: /Users/rcjsuen/.docker/cli-plugins/docker-buildx
cloud: Docker Cloud (Docker Inc.)
Version: v0.4.27
Path: /Users/rcjsuen/.docker/cli-plugins/docker-cloud
compose: Docker Compose (Docker Inc.)
Version: v2.39.4-desktop.1
Path: /Users/rcjsuen/.docker/cli-plugins/docker-compose
debug: Get a shell into any image or container (Docker Inc.)
Version: 0.0.42
Path: /Users/rcjsuen/.docker/cli-plugins/docker-debug
desktop: Docker Desktop commands (Docker Inc.)
Version: v0.2.0
Path: /Users/rcjsuen/.docker/cli-plugins/docker-desktop
extension: Manages Docker extensions (Docker Inc.)
Version: v0.2.31
Path: /Users/rcjsuen/.docker/cli-plugins/docker-extension
init: Creates Docker-related starter files for your project (Docker Inc.)
Version: v1.4.0
Path: /Users/rcjsuen/.docker/cli-plugins/docker-init
mcp: Docker MCP Plugin (Docker Inc.)
Version: v0.20.0
Path: /Users/rcjsuen/.docker/cli-plugins/docker-mcp
model: Docker Model Runner (Docker Inc.)
Version: v0.1.40
Path: /Users/rcjsuen/.docker/cli-plugins/docker-model
offload: Docker Offload (Docker Inc.)
Version: v0.4.27
Path: /Users/rcjsuen/.docker/cli-plugins/docker-offload
sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
Version: 0.6.0
Path: /Users/rcjsuen/.docker/cli-plugins/docker-sbom
scout: Docker Scout (Docker Inc.)
Version: v1.18.3
Path: /Users/rcjsuen/.docker/cli-plugins/docker-scout
Server:
Containers: 2
Running: 0
Paused: 0
Stopped: 2
Images: 39
Server Version: 28.4.0
Storage Driver: overlayfs
driver-type: io.containerd.snapshotter.v1
Logging Driver: json-file
Cgroup Driver: cgroupfs
Cgroup Version: 2
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
Discovered Devices:
cdi: docker.com/gpu=webgpu
Swarm: inactive
Runtimes: io.containerd.runc.v2 runc
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
cgroupns
Kernel Version: 6.10.14-linuxkit
Operating System: Docker Desktop
OSType: linux
Architecture: aarch64
CPUs: 14
Total Memory: 7.653GiB
Name: docker-desktop
ID: bdffc6bd-ef47-45bc-9cbc-9e2bd56bc69d
Docker Root Dir: /var/lib/docker
Debug Mode: false
HTTP Proxy: http.docker.internal:3128
HTTPS Proxy: http.docker.internal:3128
No Proxy: hubproxy.docker.internal
Labels:
com.docker.desktop.address=unix:///Users/rcjsuen/Library/Containers/com.docker.docker/Data/docker-cli.sock
Experimental: false
Insecure Registries:
hubproxy.docker.internal:5555
::1/128
127.0.0.0/8
Live Restore Enabled: false
Builders list
NAME/NODE DRIVER/ENDPOINT STATUS BUILDKIT PLATFORMS
default docker
\_ default \_ default running v0.24.0 linux/amd64 (+2), linux/arm64, linux/ppc64le, linux/s390x, (2 more)
desktop-linux* docker
\_ desktop-linux \_ desktop-linux running v0.24.0 linux/amd64 (+2), linux/arm64, linux/ppc64le, linux/s390x, (2 more)
Configuration
FROM node:24-alpine AS stage
COPY non-existent-file.txt .Debug this file with VS Code and it just terminates instead of suspending.
Build logs
Additional info
No response