grpcio: 1.78.0: patch relative path regression

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>

Author: threexc

patches/grpcio/1.78.0/0001-grpcio_tests-anchor-GatherProto-s-proto-paths-to-GRP.patch

@@ -0,0 +1,45 @@
+From 052eae2d33743cf67847521309c0201dc0bee9aa Mon Sep 17 00:00:00 2001
+From: Trevor Gamblin <tgamblin@baylibre.com>
+Date: Wed, 19 Aug 2026 12:59:15 -0400
+Subject: [PATCH] grpcio_tests: anchor GatherProto's proto paths to GRPC_STEM
+
+commands.py's GRPC_PROTO_STEM/PROTO_STEM/PYTHON_PROTO_TOP_LEVEL were made
+cwd-relative by the pyproject.toml migration (#40833), which is fine for
+the new PEP517 build path (BuildPackageProtos), but breaks the legacy
+"preprocess" command (GatherProto) used by
+tools/distrib/install_all_python_modules.sh. That script pushd's into
+src/python/grpcio_tests before invoking `setup.py preprocess`, so the
+relative path "src/proto" no longer resolves:
+
+    running preprocess
+    error: [Errno 2] No such file or directory: 'src/proto'
+
+Upstream-Status: To upstream
+
+AI-Generated: Uses Claude Sonnet 5
+
+Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>
+---
+ src/python/grpcio_tests/commands.py | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/src/python/grpcio_tests/commands.py b/src/python/grpcio_tests/commands.py
+index 997bd2a906..d3bbd0f733 100644
+--- a/src/python/grpcio_tests/commands.py
++++ b/src/python/grpcio_tests/commands.py
+@@ -32,9 +32,9 @@ from setuptools.command import test
+ PYTHON_STEM = os.path.dirname(os.path.abspath(__file__))
+ GRPC_STEM = os.path.abspath(PYTHON_STEM + "../../../../")
+ PYTHON_REL_PATH = os.path.relpath(PYTHON_STEM, start=GRPC_STEM)
+-GRPC_PROTO_STEM = os.path.join("src", "proto")
+-PROTO_STEM = os.path.join(PYTHON_REL_PATH, "src", "proto")
+-PYTHON_PROTO_TOP_LEVEL = os.path.join(PYTHON_REL_PATH, "src")
++GRPC_PROTO_STEM = os.path.join(GRPC_STEM, "src", "proto")
++PROTO_STEM = os.path.join(GRPC_STEM, PYTHON_REL_PATH, "src", "proto")
++PYTHON_PROTO_TOP_LEVEL = os.path.join(GRPC_STEM, PYTHON_REL_PATH, "src")
+ 
+ 
+ class CommandError(object):
+-- 
+2.55.0
+