fix: make first default output the executable again

CHANGELOG.md

@@ -41,6 +41,7 @@ A brief description of the categories of changes:
   `interpreter_version_info` arg.
 * (bzlmod) Correctly pass `isolated`, `quiet` and `timeout` values to `whl_library`
   and drop the defaults from the lock file.
+* (rules) The first element of the default outputs is now the executable again.
 
 ### Removed
 * (pip): Removes the `entrypoint` macro that was replaced by `py_console_script_binary` in 0.26.0.

python/private/common/py_executable.bzl

@@ -166,9 +166,10 @@ def py_executable_base_impl(ctx, *, semantics, is_test, inherited_environment =
         main_py = precompile_result.py_to_pyc_map[main_py]
     direct_pyc_files = depset(precompile_result.pyc_files)
 
-    default_outputs = precompile_result.keep_srcs + precompile_result.pyc_files
     executable = _declare_executable_file(ctx)
-    default_outputs.append(executable)
+    default_outputs = [executable]
+    default_outputs.extend(precompile_result.keep_srcs)
+    default_outputs.extend(precompile_result.pyc_files)
 
     imports = collect_imports(ctx, semantics)
 

tests/base_rules/py_executable_base_tests.bzl

@@ -18,6 +18,7 @@ load("@rules_python_internal//:rules_python_config.bzl", rp_config = "config")
 load("@rules_testing//lib:analysis_test.bzl", "analysis_test")
 load("@rules_testing//lib:truth.bzl", "matching")
 load("@rules_testing//lib:util.bzl", rt_util = "util")
+load("//python/private:util.bzl", "IS_BAZEL_7_OR_HIGHER")  # buildifier: disable=bzl-visibility
 load("//tests/base_rules:base_tests.bzl", "create_base_tests")
 load("//tests/base_rules:util.bzl", "WINDOWS_ATTR", pt_util = "util")
 load("//tests/support:support.bzl", "LINUX_X86_64", "WINDOWS_X86_64")
@@ -297,6 +298,16 @@ def _test_files_to_build_impl(env, target):
             "{package}/{test_name}_subject.py",
         ])
 
+        if IS_BAZEL_7_OR_HIGHER:
+            # As of Bazel 7, the first default output is the executable, so
+            # verify that is the case. rules_testing
+            # DepsetFileSubject.contains_exactly doesn't provide an in_order()
+            # call, nor access to the underlying depset, so we have to do things
+            # manually.
+            first_default_output = target[DefaultInfo].files.to_list()[0]
+            executable = target[DefaultInfo].files_to_run.executable
+            env.expect.that_file(first_default_output).equals(executable)
+
 def _test_name_cannot_end_in_py(name, config):
     # Bazel 5 will crash with a Java stacktrace when the native Python
     # rules have an error.