proj/portage:master commit in: lib/portage/tests/ebuild/

commit:     f05da60403fc3394954eb5cfd29e3e36d1fea504
Author:     Matt Turner <mattst88 <AT> gentoo <DOT> org>
AuthorDate: Sun Aug 16 21:39:44 2026 +0000
Commit:     Matt Turner <mattst88 <AT> gentoo <DOT> org>
CommitDate: Mon Aug 17 21:07:17 2026 +0000
URL:        https://gitweb.gentoo.org/proj/portage.git/commit/?id=f05da604

tests: cover self update with a relocated install

Emulate a portage update which installs to a different location: copy
the installed tree, run _prepare_self_update(), delete the tree, and
then import modules which were not imported beforehand, both in the
process itself and in a child. Repeat for the fork and forkserver
start methods.

Bug: https://bugs.gentoo.org/976616
Signed-off-by: Matt Turner <mattst88 <AT> gentoo.org>

 lib/portage/tests/ebuild/meson.build               |  1 +
 .../tests/ebuild/test_prepare_self_update.py       | 94 ++++++++++++++++++++++
 2 files changed, 95 insertions(+)

diff --git a/lib/portage/tests/ebuild/meson.build b/lib/portage/tests/ebuild/meson.build
index 6ef546f51..bca1c56d4 100644
--- a/lib/portage/tests/ebuild/meson.build
+++ b/lib/portage/tests/ebuild/meson.build
@@ -6,6 +6,7 @@ py.install_sources(
         'test_doebuild_spawn.py',
         'test_fetch.py',
         'test_ipc_daemon.py',
+        'test_prepare_self_update.py',
         'test_spawn.py',
         'test_use_expand_incremental.py',
         '__init__.py',

diff --git a/lib/portage/tests/ebuild/test_prepare_self_update.py b/lib/portage/tests/ebuild/test_prepare_self_update.py
new file mode 100644
index 000000000..9cb1ed753
--- /dev/null
+++ b/lib/portage/tests/ebuild/test_prepare_self_update.py
@@ -0,0 +1,94 @@
+# Copyright 2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+import os
+import shutil
+import subprocess
+import tempfile
+
+import portage
+from portage.const import PORTAGE_BIN_PATH, PORTAGE_PYM_PATH
+from portage.tests import TestCase
+
+# Runs in a subprocess with an installed copy of portage which is
+# deleted after _prepare_self_update() has run, in order to emulate a
+# self update which installs to a different location, as happens when
+# PYTHON_TARGETS changes (bug 976616).
+_SCRIPT = """
+import multiprocessing
+import os
+import shutil
+import sys
+
+def child():
+    import portage.dbapi.vartree
+
+
+if __name__ == "__main__":
+    sys.path.insert(0, sys.argv[1])
+
+    import portage
+    from portage.package.ebuild.doebuild import _prepare_self_update
+
+    # The modules imported below must not be imported before the update.
+    assert "portage.util.env_update" not in sys.modules
+    assert "portage.dbapi.vartree" not in sys.modules
+
+    _prepare_self_update({"PORTAGE_TMPDIR": sys.argv[2]})
+
+    shutil.rmtree(os.path.dirname(sys.argv[1]))
+
+    import portage.util.env_update
+
+    ctx = multiprocessing.get_context(sys.argv[3])
+    proc = ctx.Process(target=child)
+    proc.start()
+    proc.join()
+    sys.exit(proc.exitcode)
+"""
+
+
+class PrepareSelfUpdateTestCase(TestCase):
+    def testPrepareSelfUpdate(self):
+        tmpdir = tempfile.mkdtemp()
+        try:
+            script = os.path.join(tmpdir, "self_update.py")
+            with open(script, "w") as f:
+                f.write(_SCRIPT)
+
+            # PYTHONPATH would provide a second copy of the modules
+            # which are expected to become unimportable.
+            env = os.environ.copy()
+            env.pop("PYTHONPATH", None)
+
+            for start_method in ("fork", "forkserver"):
+                # The installed copy is deleted by the subprocess, so
+                # create a fresh one for each start method.
+                base_path = os.path.join(tmpdir, f"base-{start_method}")
+                pym_path = os.path.join(base_path, os.path.basename(PORTAGE_PYM_PATH))
+                os.mkdir(base_path)
+                shutil.copytree(PORTAGE_PYM_PATH, pym_path, symlinks=True)
+                shutil.copytree(
+                    PORTAGE_BIN_PATH,
+                    os.path.join(base_path, os.path.basename(PORTAGE_BIN_PATH)),
+                    symlinks=True,
+                )
+
+                proc = subprocess.run(
+                    [
+                        portage._python_interpreter,
+                        script,
+                        pym_path,
+                        tmpdir,
+                        start_method,
+                    ],
+                    env=env,
+                    stderr=subprocess.PIPE,
+                )
+                self.assertEqual(
+                    proc.returncode,
+                    os.EX_OK,
+                    msg=proc.stderr.decode(errors="replace"),
+                )
+        finally:
+            shutil.rmtree(tmpdir, ignore_errors=True)