Unable to collect coverage for subprocesses running in different directories

[nahco314]

Describe the bug
In Python 3.8.2, coverage 6.5.0.

I am trying to measure the coverage of a test using subprocess.

If I start a subprocess in a different directory than the original directory, a data file will be generated in that directory.

Moving the data file to the original directory and combine&report will generate a report that does not reflect the execution of the sub-process.

To Reproduce

A simple example :
./main.py

import os
import subprocess

orig = os.getcwd()
os.chdir("./d")
subprocess.run(
    ["python", f"{orig}/sub.py"],
    env={
        **os.environ,
        "COVERAGE_PROCESS_START": f"{orig}/pyproject.toml",
        "PYTHONPATH": f"{orig}",
    },
)
os.chdir(orig)

./sub.py

print("Hello,World!")

./pyproject.toml

[tool.coverage.run]
branch = true
source = ["."]
parallel = true
omit = ["sitecustomize.py"]

./sitecustomize.py

import coverage
coverage.process_startup()

print("Loaded!")

$ coverage run main.py
Loaded!
Hello,World!
$ ls -a ./d
. .. .coverage.nahco314-pc.16642.385055

Expected behavior
I would like coverage results that include Python execution in sub-processes.

Additional context
If only directory moves are pulled out and executed, coverage is generated successfully.

Output of coverage debug sys:

-- sys -------------------------------------------------------
               coverage_version: 6.5.0
                coverage_module: /home/nahco314/PycharmProjects/pythonProject6/venv/lib/python3.8/site-packages/coverage/__init__.py
                         tracer: -none-
                        CTracer: available
           plugins.file_tracers: -none-
            plugins.configurers: -none-
      plugins.context_switchers: -none-
              configs_attempted: .coveragerc
                                 setup.cfg
                                 tox.ini
                                 pyproject.toml
                   configs_read: /home/nahco314/PycharmProjects/pythonProject6/pyproject.toml
                    config_file: /home/nahco314/PycharmProjects/pythonProject6/pyproject.toml
                config_contents: b'[tool.coverage.run]\nbranch = true\nsource = ["."]\nparallel = true\nomit = ["sitecustomize.py"]\n'
                      data_file: -none-
                         python: 3.8.2 (default, Sep 22 2022, 00:18:42) [GCC 11.2.0]
                       platform: Linux-5.15.0-53-generic-x86_64-with-glibc2.35
                 implementation: CPython
                     executable: /home/nahco314/PycharmProjects/pythonProject6/venv/bin/python
                   def_encoding: utf-8
                    fs_encoding: utf-8
                            pid: 27900
                            cwd: /home/nahco314/PycharmProjects/pythonProject6
                           path: /home/nahco314/PycharmProjects/pythonProject6/venv/bin
                                 /home/nahco314/.pyenv/versions/3.8.2/lib/python38.zip
                                 /home/nahco314/.pyenv/versions/3.8.2/lib/python3.8
                                 /home/nahco314/.pyenv/versions/3.8.2/lib/python3.8/lib-dynload
                                 /home/nahco314/PycharmProjects/pythonProject6/venv/lib/python3.8/site-packages
                    environment: HOME = /home/nahco314
                                 PYENV_DIR = /home/nahco314/.local/share/JetBrains/Toolbox/apps/PyCharm-P/ch-0/223.7571.203/bin
                                 PYENV_HOOK_PATH = /home/nahco314/.pyenv/pyenv.d:/usr/local/etc/pyenv.d:/etc/pyenv.d:/usr/lib/pyenv/hooks
                                 PYENV_ROOT = /home/nahco314/.pyenv
                                 PYENV_SHELL = bash
                                 PYENV_VERSION = 3.11.0
                   command_line: /home/nahco314/PycharmProjects/pythonProject6/venv/bin/coverage debug sys
                sqlite3_version: 2.6.0
         sqlite3_sqlite_version: 3.37.2
             sqlite3_temp_store: 0
        sqlite3_compile_options: ATOMIC_INTRINSICS=1, COMPILER=gcc-11.3.0, DEFAULT_AUTOVACUUM,
                                 DEFAULT_CACHE_SIZE=-2000, DEFAULT_FILE_FORMAT=4,
                                 DEFAULT_JOURNAL_SIZE_LIMIT=-1, DEFAULT_MMAP_SIZE=0, DEFAULT_PAGE_SIZE=4096,
                                 DEFAULT_PCACHE_INITSZ=20, DEFAULT_RECURSIVE_TRIGGERS,
                                 DEFAULT_SECTOR_SIZE=4096, DEFAULT_SYNCHRONOUS=2,
                                 DEFAULT_WAL_AUTOCHECKPOINT=1000, DEFAULT_WAL_SYNCHRONOUS=2,
                                 DEFAULT_WORKER_THREADS=0, ENABLE_COLUMN_METADATA, ENABLE_DBSTAT_VTAB,
                                 ENABLE_FTS3, ENABLE_FTS3_PARENTHESIS, ENABLE_FTS3_TOKENIZER, ENABLE_FTS4,
                                 ENABLE_FTS5, ENABLE_JSON1, ENABLE_LOAD_EXTENSION, ENABLE_MATH_FUNCTIONS,
                                 ENABLE_PREUPDATE_HOOK, ENABLE_RTREE, ENABLE_SESSION, ENABLE_STMTVTAB,
                                 ENABLE_UNLOCK_NOTIFY, ENABLE_UPDATE_DELETE_LIMIT, HAVE_ISNAN,
                                 LIKE_DOESNT_MATCH_BLOBS, MALLOC_SOFT_LIMIT=1024, MAX_ATTACHED=10,
                                 MAX_COLUMN=2000, MAX_COMPOUND_SELECT=500, MAX_DEFAULT_PAGE_SIZE=32768,
                                 MAX_EXPR_DEPTH=1000, MAX_FUNCTION_ARG=127, MAX_LENGTH=1000000000,
                                 MAX_LIKE_PATTERN_LENGTH=50000, MAX_MMAP_SIZE=0x7fff0000,
                                 MAX_PAGE_COUNT=1073741823, MAX_PAGE_SIZE=65536, MAX_SCHEMA_RETRY=25,
                                 MAX_SQL_LENGTH=1000000000, MAX_TRIGGER_DEPTH=1000,
                                 MAX_VARIABLE_NUMBER=250000, MAX_VDBE_OP=250000000, MAX_WORKER_THREADS=8,
                                 MUTEX_PTHREADS, OMIT_LOOKASIDE, SECURE_DELETE, SOUNDEX, SYSTEM_MALLOC,
                                 TEMP_STORE=1, THREADSAFE=1, USE_URI