Failed clang Release+Asserts dir cleanup may lead to incorrect headers being used remotely

[goodov]

This logic may choose an incorrect clang directory if gclient sync fails to remove an old directory:

reclient-configs/configure_reclient.py

Lines 171 to 188 in 7851c93

	# Find "include" directory inside clang installation. This directory
	# will be symlinked by remote wrapper for cross-compilation to work. The
	# path is clang-version dependent, so don't hardcode it.
	clang_include_dir_glob = glob.glob(
	f'{Paths.clang_base_path}/lib/**/include', recursive=True)
	if not clang_include_dir_glob:
	raise RuntimeError(
	f'Cannot find lib/**/include dir in {Paths.clang_base_path}. '
	f'If clang directory structure has changed, please update '
	f'{Paths.abspath(__file__)} and {template_file} if required.')
	clang_include_dir_abs = Paths.normpath(clang_include_dir_glob[0])
	assert os.path.isdir(clang_include_dir_abs), clang_include_dir_abs
	clang_include_dir = Paths.relpath(clang_include_dir_abs,
	Paths.build_dir)
	linux_clang_include_dir = Paths.relpath(
	clang_include_dir_abs.replace(Paths.clang_base_path,
	Paths.linux_clang_base_path),
	Paths.build_dir)

This leads to clang_remote_wrapper trying to run a compiler with a symlink pointing nowhere, i.e. instead of:

clang_include_dir="../../third_party/llvm-build/Release+Asserts/lib/clang/20/include"
linux_clang_include_dir="../../third_party/llvm-build/Release+Asserts_linux/lib/clang/20/include"

we get:

clang_include_dir="../../third_party/llvm-build/Release+Asserts/lib/clang/19/include"
linux_clang_include_dir="../../third_party/llvm-build/Release+Asserts_linux/lib/clang/19/include"

A more robust approach is to search for the lib/**/include directory remotely and symlink it right in the clang_remote_wrapper script.

Another approach is to sort found directories and choose the last one instead of the first one.