--noexperimental_check_external_repository_files doesn't work with Bzlmod repo

[meteorcloudy]

Description of the bug:

bazel/src/test/shell/bazel/check_external_files_test.sh

Lines 115 to 125 in e5b8f5a

	test_check_external_files() {
	setup_remote
	bazel build @remote//:g >& "$TEST_log" || fail "Expected build to succeed"
	echo "broken file" > bazel-main/external/remote/BUILD
	# The --noexperimental_check_external_repository_files flag doesn't notice the file is broken
	bazel build --noexperimental_check_external_repository_files @remote//:g >& "$TEST_log" || fail "Expected build to succeed"
	bazel build @remote//:g >& "$TEST_log" && fail "Expected build to fail" || true
	expect_log "no such target '@@remote//:g'"
	}

If we migrate this test case to Bzlmod:

setup_remote() {
  WRKDIR=$(mktemp -d "${TEST_TMPDIR}/testXXXXXX")
  cd "${WRKDIR}"

  mkdir remote
  (
    cd remote
    echo 'genrule(name="g", outs=["go"], cmd="echo GO > $@")' > BUILD
  )
  tar cvf remote.tar remote
  rm -rf remote

  mkdir main
  cd main
  cat >> MODULE.bazel <<EOF
http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
  name="remote",
  strip_prefix="remote",
  urls=["$(get_extrepourl $WRKDIR)/remote.tar"],
)
EOF
}

test_check_external_files() {
  setup_remote
  bazel build @remote//:g >& "$TEST_log" || fail "Expected build to succeed"

  echo "broken file" > bazel-main/external/+_repo_rules+remote/BUILD
  # The --noexperimental_check_external_repository_files flag doesn't notice the file is broken
  bazel build --noexperimental_check_external_repository_files @remote//:g >& "$TEST_log" || fail "Expected build to succeed"

  bazel build @remote//:g >& "$TEST_log" && fail "Expected build to fail" || true
  expect_log "no such target '@@+_repo_rules+remote//:g'"
}

The test fails with:

ERROR: /usr/local/google/home/pcloudy/.cache/bazel/_bazel_pcloudy/4c5ccabacef1ddac6600d71a1b8bfa58/sandbox/linux-sandbox/2849/execroot/_main/_tmp/6ae13531c753d159158e8eb86f5df1eb/root/120a11317afcb80d507344874cf9f97b/external/+_repo_rules+remote/BUILD:1:8: syntax error at 'file': expected newline

which means --noexperimental_check_external_repository_files doesn't work as expected.

Which category does this issue belong to?

No response

What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Change the test as above and run

bazel test //src/test/shell/bazel:check_external_files_test --test_filter test_check_external_files

Which operating system are you running Bazel on?

No response

What is the output of bazel info release?

No response

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

No response

If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

No response

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

No response

[Wyverald]

Huh. I tried the exact thing you wrote, and the test passed for me. Will send a PR.