`make regen-all` fails on conflict markers in argument clinic code

[nineteendo]

Bug report

Bug description:

Output:

gcc  -fno-strict-overflow -Wsign-compare -Wunreachable-code -DNDEBUG -g -O3 -Wall    -std=c11 -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wstrict-prototypes -Werror=implicit-function-declaration -fvisibility=hidden  -I./Include/internal -I./Include/internal/mimalloc  -I. -I./Include    -DPy_BUILD_CORE_BUILTIN -c ./Modules/posixmodule.c -o Modules/posixmodule.o
In file included from ./Modules/posixmodule.c:15944:
./Modules/clinic/posixmodule.c.h:13087:1: error: version control conflict marker in file
<<<<<<< HEAD
^
1 error generated.
make: *** [Modules/posixmodule.o] Error 1

This makes it harder to fix merge conflicts, see: https://discuss.python.org/t/reducing-merge-conflicts-in-generated-code/68537/8

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

[rruuaanng]

Can you give a minimum trigger? I can't reproduce the issue (I'll try to fix it later, but that doesn't affect anyone else from being able to complete the issue)

[nineteendo]

You can just insert a conflict marker in Modules/posixmodule.c.h:

<<<<<<< HEAD
/*[clinic end generated code: output=1da32369b7d9fd4b input=a9049054013a1b77]*/
=======
/*[clinic end generated code: output=1da32369b7d9fd4b input=a9049054013a1b77]*/
>>>>>>> main

[erlend-aasland]

Please do not create multiple issues for the same problems. Please both of you, see the devguide for how to use the bug tracker.

Duplicate of #126206.

[nineteendo]

While this is related, this wouldn't necessary be fixed if the other "bug" was fixed. You could have just said that your comment on the other thread also applies here.