ci(build): fix find|head broken-pipe flake in Build Sample Tests

[ubercylon8]

Problem

The Build Sample Tests workflow's Build tests (Linux/macOS only) step failed intermittently with find: write error (seen on PR #65).

Root cause is a classic broken-pipe race in .github/workflows/build.yml:

FIRST_TEST=$(find tests_source -name "go.mod" ... | head -1 | xargs dirname)

head -1 closes the pipe after the first line; find then errors writing its remaining output, and set -o pipefail (+ -e) promotes that to a step failure. Adding more test directories made find write more, tipping the latent race into a consistent failure.

Note: the step's actual gobuild build is guarded with || echo, so this was never a real build/compile failure — purely the shell pipeline.

Fix

Use find ... -print -quit, which stops at the first match with no downstream pipe to break (supported by both GNU and BSD find, so it holds on the ubuntu and macOS runners), and guard on the resolved go.mod path:

FIRST_GOMOD=$(find tests_source -name "go.mod" ... -print -quit)
if [ -n "$FIRST_GOMOD" ]; then
  FIRST_TEST=$(dirname "$FIRST_GOMOD")
  ./utils/gobuild build "$FIRST_TEST" || echo "..."
fi

Scope

CI-only, one file. Independent of the test work in #65 (which is mergeable regardless — main has no required checks). Opening separately to keep that PR scoped to its tests.

🤖 Generated with Claude Code