chore: make apidiff test more robust and informative

[justinsb]

• Use exec so that if the prow job is killed, the script is killed too
• Print full apidiff output in both success and failure cases

NONE

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[justinsb]

I'm slightly at a loss as to why sometimes apidiff hangs for 50+ hours, I'm guessing the prow job is OOM killed or something like that.

[justinsb]

Confirmed an OOM kill in the prow description for the test:

Terminated (OOMKilled - Activated service account credentials for: [[email protected]] + WRAPPED_COMMAND_PID=28 + wait 28 + ./scripts/ci-apidiff.sh (unset) (unset) APIDIFF_OLD_COMMIT="521ba6f23d3accf27d3a0cfa0fbf00c33921ff34" hack/verify-apidiff *** Running go-apidiff *** go: downloading github.com/joelanford/go-apidiff v0.8.3 go: downloading github.com/spf13/cobra v1.9.1 go: downloading github.com/go-git/go-billy/v5 v5.6.2 go: downloading golang.org/x/sys v0.33.0 go: downloading golang.org/x/tools v0.33.0 go: downloading github.com/go-git/go-git/v5 v5.16.0 go: downloading golang.org/x/exp v0.0.0-20250506013437-ce4c2cf36ca6 go: downloading github.com/spf13/pflag v1.0.6 go: downloading github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 go: downloading github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 go: downloading github.com/ProtonMail/go-crypto v1.2.0 go: downloading dario.cat/mergo v1.0.2 go: downloading github.com/cyphar/filepath-securejoin v0.4.1 go: downloading github.com/sergi/go-diff v1.3.2-0.20230802210424-5b0b94c5c0d3 go: downloading github.com/pjbgf/sha1cd v0.3.2 go: downloading github.com/emirpasic/gods v1.18.1 go: downloading github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 go: downloading github.com/kevinburke/ssh_config v1.2.0 go: downloading github.com/skeema/knownhosts v1.3.1 go: downloading github.com/xanzy/ssh-agent v0.3.3 go: downloading golang.org/x/crypto v0.38.0 go: downloading golang.org/x/net v0.40.0 go: downloading gopkg.in/warnings.v0 v0.1.2 go: downloading github.com/cloudflare/circl v1.6.1 go: downloading golang.org/x/sync v0.14.0 go: downloading golang.org/x/mod v0.24.0 ) at 2025-10-06 16:34:58 +0000 UTC with exit code 137

[justinsb]

Also raising memory in kubernetes/test-infra#35686 to mirror apidiff CAPA jobs

[salasberryfin]

Thanks @justinsb.

/lgtm