kubectl version seems broken since 579

[albanpeignier]

Issue Description

The kubectl version returns strange values: major and minor attributes are empty. gitVersion and gitCommit contain like raw patterns.

kubectl version --client --output=json
{
  "clientVersion": {
    "major": "",
    "minor": "",
    "gitVersion": "v0.0.0-master+$Format:%H$",
    "gitCommit": "$Format:%H$",
    "gitTreeState": "",
    "buildDate": "2026-07-22T17:11:40Z",
    "goVersion": "go1.26.5",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.7.1"
}

Expected Behavior

By using the latest kubectl binary, the output seems normal:

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
./kubectl version --client --output=json
{
  "clientVersion": {
    "major": "1",
    "minor": "36",
    "gitVersion": "v1.36.3",
    "gitCommit": "0f29094e5b73085e3802ecc1298ecae13866bfe6",
    "gitTreeState": "clean",
    "buildDate": "2026-07-22T18:10:35Z",
    "goVersion": "go1.26.5",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.8.1"
}

Steps to Reproduce

Use google/cloud-sdk:579 or google/cloud-sdk:580 images and run kubectl version --client or kubectl version --client --output=json:

docker run --rm -it google/cloud-sdk:579.0.0-slim sh -c "apt install -y kubectl && kubectl version --client --output=json"
[...]
Setting up kubectl (1:579.0.0-0) ...
{
  "clientVersion": {
    "major": "",
    "minor": "",
    "gitVersion": "v0.0.0-master+$Format:%H$",
    "gitCommit": "$Format:%H$",
    "gitTreeState": "",
    "buildDate": "2026-07-22T17:11:40Z",
    "goVersion": "go1.26.5",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.7.1"
}

docker run --rm -it google/cloud-sdk:580.0.0-slim sh -c "apt install -y -q kubectl && kubectl version --client --output=json"
[...]
Setting up kubectl (1:580.0.0-0) ...
{
  "clientVersion": {
    "major": "",
    "minor": "",
    "gitVersion": "v0.0.0-master+$Format:%H$",
    "gitCommit": "$Format:%H$",
    "gitTreeState": "",
    "buildDate": "2026-07-22T17:11:40Z",
    "goVersion": "go1.26.5",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.7.1"
}

Workaround

Use google/cloud-sdk:578 or older (but kubectl is 1.35):

➜ docker run --rm -it google/cloud-sdk:578.0.0-slim sh -c "apt install -y -q kubectl && kubectl version --client --output=json"
[...]
Setting up kubectl (1:578.0.0-0) ...
{
  "clientVersion": {
    "major": "1",
    "minor": "35+",
    "gitVersion": "v1.35.6-dispatcher",
    "gitCommit": "09fd156955ddedeb343e16fed4068eded91114c2",
    "gitTreeState": "clean",
    "buildDate": "2026-07-08T21:21:16Z",
    "goVersion": "go1.26.4",
    "compiler": "gc",
    "platform": "linux/amd64"
  },
  "kustomizeVersion": "v5.7.1"
}

[YonathanZetune]

This should be fixed now in gcloud CLI version 583.0.0