What is the proper way to apply a patch where the source is in a subdirectory (e.g. subprojects/)

[tjwilli58]

9567.patch
I'm trying to rebuild gst-python to apply the patch from this MR: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9567.

Edited projects/gstreamer.py to have

            patches=[
                "9567.patch",
            ],  

and put the patch in patches/gst-python/.

I get this error when trying to build:

Building project gst-python (1.26.3)
can't find file to patch at input line 23
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|From b051285e03486ab134e6d01ff49be54884975a0a Mon Sep 17 00:00:00 2001
|From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <[email protected]>
|Date: Mon, 18 Aug 2025 14:13:55 +0300
|Subject: [PATCH] python: Handle buffer PTS/DTS/duration/offset/offset-end as
| unsigned long long
|
|Previously these fields were truncated to 32 bits on 32 bit platforms and
|64 bit Windows because of using `unsigned long`.
|
|Thanks to Tim Williams for reporting and debugging this issue.
|
|Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/4603
|
|Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/9567>
|---
| subprojects/gst-python/gi/overrides/gstmodule.c | 10 +++++-----
| 1 file changed, 5 insertions(+), 5 deletions(-)
|
|diff --git a/subprojects/gst-python/gi/overrides/gstmodule.c b/subprojects/gst-python/gi/overrides/gstmodule.c
|index 4ff5cc429d86..72431421d591 100644
|--- a/subprojects/gst-python/gi/overrides/gstmodule.c
|+++ b/subprojects/gst-python/gi/overrides/gstmodule.c
--------------------------
File to patch:
Skip this patch? [y]
Skipping patch.
5 out of 5 hunks ignored
Traceback (most recent call last):
  File "C:\FieldSoftware\gvsbuild\gvsbuild\utils\builder.py", line 555, in build
    if self.__build_one(p):
       ^^^^^^^^^^^^^^^^^^^
  File "C:\FieldSoftware\gvsbuild\gvsbuild\utils\builder.py", line 685, in __build_one
    proj.patch()
  File "C:\FieldSoftware\gvsbuild\gvsbuild\utils\base_project.py", line 440, in patch
    self.builder.exec_msys(
  File "C:\FieldSoftware\gvsbuild\gvsbuild\utils\builder.py", line 1011, in exec_msys
    self.__execute(
  File "C:\FieldSoftware\gvsbuild\gvsbuild\utils\builder.py", line 1043, in __execute
    subprocess.check_call(args, cwd=working_dir, env=env, shell=True)
  File "C:\Users\Bruce\AppData\Local\Programs\Python\Python312\Lib\subprocess.py", line 413, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['patch', '-p1', '-i', '9567.patch']' returned non-zero exit status 1.
Error: gst-python build failed

I found that by editing the patch file to remove /subprojects/gst-python, the patch gets applied.

--- a/gi/overrides/gstmodule.c
+++ b/gi/overrides/gstmodule.c

Is this the proper way?

[danyeaw]

Hi @tjwilli58 - yes, that's the way for GStreamer since it is in a monorepo.