chore: fix test suite on macOS (#12780)

MacOS uses a very old version of bash where `"${FOO[@]}"` fails if `set
-u` is enabled and `FOO` is undefined. Newer versions of bash expand
this to zero arguments instead.

Also, `lint.py` used the shebang `#!/usr/bin/env python` instead of
`python3`, which fails on some systems.

In CI, all macos tests run on nscloud runners. Presumably, they have
installed newer versions of various software, hence this didn't break in
CI.

script/gen_constants_cpp.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #
 # Copyright (c) 2015 Microsoft Corporation. All rights reserved.

script/gen_tokens_cpp.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #
 # Copyright (c) 2015 Microsoft Corporation. All rights reserved.

tests/CMakeLists.txt

@@ -407,7 +407,7 @@ endforeach(T)
 
 # Lint test suite and parts of the repository.
 # Must not run in parallel with any other tests that may create or delete files.
-add_test(NAME lint.py COMMAND python lint.py WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+add_test(NAME lint.py COMMAND python3 lint.py WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 set_tests_properties(lint.py PROPERTIES RUN_SERIAL TRUE)
 
 add_test_pile(compile *.lean BENCH PART2)

tests/lint.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
@@ -190,11 +190,10 @@ for file in Path().glob("**/run_bench"):
         nag("has env_test.sh", file)
 
 
-# File confusion by case insensitive filesystems,
-# applies to entire repository
+# File confusion by case insensitive filesystems
 
 seen: set[str] = set()
-for file in Path("..").glob("**/*"):
+for file in Path().glob("**/*"):
     path = str(file).lower()
     if path in seen:
         nag("case sensitive", file)

tests/util.sh

@@ -1,4 +1,4 @@
-set -eu
+set -e
 
 DIFF="diff -au --strip-trailing-cr --color=always"
 ulimit -S -s ${TEST_STACK_SIZE:-8192}