tools/show_paths.bzl: check that provider_map isn't None

Otherwise it can fail:
$ bazel cquery pkg/p9/... --output=starlark --starlark:file=tools/show_paths.bzl
...
ERROR: Starlark evaluation error for //pkg/p9/p9test:mockgen:
Traceback (most recent call last):
	File "tools/show_paths.bzl", line 8, column 32, in format
Error: 'NoneType' value has no field or method 'get'
PiperOrigin-RevId: 396457764

.buildkite/pipeline.yaml

@@ -169,6 +169,11 @@ steps:
     label: ":mechanical_arm: ARM"
     command: make arm-qemu-smoke-test
 
+  # Build everything.
+  - <<: *common
+    label: ":world_map: Build everything"
+    command: "make build OPTIONS=--build_tag_filters=-nogo TARGETS=//..."
+
   # Run basic benchmarks smoke tests (no upload).
   - <<: *common
     label: ":fire: Benchmarks smoke test"

test/util/BUILD

@@ -352,7 +352,6 @@ cc_library(
 cc_library(
     name = "benchmark_main",
     testonly = 1,
-    srcs = ["benchmark_main.cc"],
     linkstatic = 1,
     deps = [
         ":test_util",

test/util/benchmark_main.cc

@@ -1,64 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "gtest/gtest.h"
-#include "absl/flags/flag.h"
-#include "third_party/benchmark/src/commandlineflags.h"
-#include "test/util/test_util.h"
-
-DECLARE_bool(benchmark_list_internal);
-DECLARE_string(benchmark_filter_internal);
-ABSL_FLAG(bool, benchmark_enable_random_interleaving_internal, false,
-          "forward");
-ABSL_FLAG(double, benchmark_min_time_internal, -1.0, "forward");
-ABSL_FLAG(int, benchmark_repetitions_internal, 1, "forward");
-
-// From //third_party/benchmark.
-//
-// These conflict with the internal definitions, but all the benchmark binaries
-// link against the external benchmark library for compatibility with the open
-// source build. We massage the internal-only flags into the external ones, and
-// call the function to actually run all registered external benchmarks.
-namespace benchmark {
-BM_DECLARE_bool(benchmark_list_tests);
-BM_DECLARE_string(benchmark_filter);
-BM_DECLARE_int32(benchmark_repetitions);
-BM_DECLARE_double(benchmark_min_time);
-BM_DECLARE_bool(benchmark_enable_random_interleaving);
-extern size_t RunSpecifiedBenchmarks();
-}  // namespace benchmark
-
-using benchmark::FLAGS_benchmark_enable_random_interleaving;
-using benchmark::FLAGS_benchmark_filter;
-using benchmark::FLAGS_benchmark_list_tests;
-using benchmark::FLAGS_benchmark_min_time;
-using benchmark::FLAGS_benchmark_repetitions;
-
-int main(int argc, char** argv) {
-  gvisor::testing::TestInit(&argc, &argv);
-  absl::SetFlag(&FLAGS_benchmark_list_tests,
-                absl::GetFlag(FLAGS_benchmark_list_internal));
-  absl::SetFlag(&FLAGS_benchmark_filter,
-                absl::GetFlag(FLAGS_benchmark_filter_internal));
-  absl::SetFlag(&FLAGS_benchmark_repetitions,
-                absl::GetFlag(FLAGS_benchmark_repetitions_internal));
-  absl::SetFlag(
-      &FLAGS_benchmark_enable_random_interleaving,
-      absl::GetFlag(FLAGS_benchmark_enable_random_interleaving_internal));
-  absl::SetFlag(&FLAGS_benchmark_min_time,
-                absl::GetFlag(FLAGS_benchmark_min_time_internal));
-
-  benchmark::RunSpecifiedBenchmarks();
-  return 0;
-}

tools/bazel.mk

@@ -186,8 +186,8 @@ build_paths = \
   (set -euo pipefail; \
   $(call wrapper,$(BAZEL) build $(BASE_OPTIONS) $(BAZEL_OPTIONS) $(1)) && \
   $(call wrapper,$(BAZEL) cquery $(BASE_OPTIONS) $(BAZEL_OPTIONS) $(1) --output=starlark --starlark:file=tools/show_paths.bzl) \
-  | xargs -r -n 1 -I {} readlink -f "{}" \
-  | xargs -r -n 1 -I {} bash -c 'set -xeuo pipefail; $(2)')
+  | xargs -r -n 1 -I {} bash -c 'test -e "{}" || exit 0; readlink -f "{}"' \
+  | xargs -r -n 1 -I {} bash -c 'set -euo pipefail; $(2)')
 
 clean = $(call header,CLEAN) && $(call wrapper,$(BAZEL) clean)
 build = $(call header,BUILD $(1)) && $(call build_paths,$(1),echo {})

tools/show_paths.bzl

@@ -2,6 +2,8 @@
 
 def format(target):
     provider_map = providers(target)
+    if not provider_map:
+        return ""
     outputs = dict()
 
     # Try to resolve in order.