build_with_container.sh fails silently (no output) when /etc/group has no docker entry

What happened:

On macOS, the default build fails immediately without printing any diagnostic output:

Even the script's first echo is never reached, so there is no indication of what went wrong.

The issue is caused by this line in hack/make-rules/build_with_container.sh:

DOCKER_GID="${DOCKER_GID:-$(grep '^docker:' /etc/group | cut -f3 -d:)}"   

On macOS, /etc/group does not contain a docker entry because Docker Desktop does not create one. Since the script uses both set -o errexit and set -o pipefail, the failed grep causes the script to exit immediately.

As a result, the build stops before the script's echo and before Docker is ever invoked.

This affects the default build path because BUILD_WITH_CONTAINER is set to true in the Makefile.

What you expected to happen:

Running:

make all WHAT=cloudcore

on macOS should either:

1. build successfully inside the container, or
2. fail with a clear error message explaining what is missing and how to proceed.

A silent Error 1 makes the problem difficult to diagnose.

Steps to reproduce:

On macOS with Docker Desktop installed and running:

git clone https://github.com/kubeedge/kubeedge
cd kubeedge
make all WHAT=cloudcore

The underlying failure can also be reproduced independently:

$ bash -c 'set -o errexit; set -o pipefail; \
  DOCKER_GID="${DOCKER_GID:-$(grep "^docker:" /etc/group | cut -f3 -d:)}"; \
  echo "reached echo, GID=$DOCKER_GID"'
$ echo $?
1 

The echo is never reached.

Possible fix:

One approach is to tolerate the missing docker group and only pass the -u option when a GID is available:

DOCKER_GID="${DOCKER_GID:-$(grep '^docker:' /etc/group 2>/dev/null | cut -f3 -d: || true)}"

USER_OPTS=()
if [[ -n "${DOCKER_GID}" ]]; then
  USER_OPTS=(-u "${UID}:${DOCKER_GID}")
fi 

This would allow Docker Desktop on macOS to handle bind-mount ownership without requiring a docker group entry.

If container builds are intentionally not supported on macOS, the script should instead exit with an explicit message such as:

Container builds are not supported on macOS. Please run with BUILD_WITH_CONTAINER=false.

Existing workarounds:

The following workarounds currently work, but are not discoverable from the error:

make all WHAT=cloudcore BUILD_WITH_CONTAINER=false

or:

DOCKER_GID=0 make all WHAT=cloudcore 

Related issue:

This appears to be the same root cause reported in #3881 (fix build_with_container.sh) in May 2022. That PR was not reviewed, became stale in July 2022, and was automatically closed in August 2022. The affected line remains unchanged on master.

macOS is otherwise handled explicitly in the repository's tooling. For example, hack/lib/lint.sh contains darwin-specific handling and provides instructions for installing GNU sed on macOS.

This makes the current behavior of build_with_container.sh inconsistent with the rest of the tooling.

Environment:

• KubeEdge: master @ d062d2983
• Kubernetes: n/a — build-time issue, no cluster involved
• Hardware: Apple Silicon (arm64)
• OS: macOS 27.0
• Go: go1.23.12 darwin/arm64
• Docker: 29.8.0
• GNU Make: 3.81 (macOS default)