[bug] relative file paths when using Cache

[jan-janssen]

Example code:

from executorlib.api import TestClusterExecutor
from time import sleep
import shutil
import os

funct_str = """
from time import sleep

def echo_with_delay(i):
    sleep(10)
    return i
"""

with open("myfunctions.py", "w") as f:
    f.write(funct_str)

from myfunctions import echo_with_delay
# os.environ["PYTHONPATH"] = os.path.abspath(os.getcwd())
exe = TestClusterExecutor()
f1 = exe.submit(echo_with_delay, 1)
f2 = exe.submit(echo_with_delay, 2)
f3 = exe.submit(echo_with_delay, 3)
exe.shutdown(wait=True, cancel_futures=False)

Error:

Traceback (most recent call last):
  File "/srv/conda/envs/notebook/lib/python3.13/site-packages/executorlib/backend/cache_serial.py", line 6, in <module>
    backend_execute_task_in_file(file_name=sys.argv[1])
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^
  File "/srv/conda/envs/notebook/lib/python3.13/site-packages/executorlib/task_scheduler/file/backend.py", line 71, in backend_execute_task_in_file
    apply_dict = backend_load_file(file_name=file_name)
  File "/srv/conda/envs/notebook/lib/python3.13/site-packages/executorlib/task_scheduler/file/backend.py", line 21, in backend_load_file
    apply_dict = load(file_name=file_name)
  File "/srv/conda/envs/notebook/lib/python3.13/site-packages/executorlib/standalone/hdf.py", line 54, in load
    data_dict["fn"] = cloudpickle.loads(np.void(hdf["/function"]))
                      ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'myfunctions'

The error does not appear on MacOS and adding the current path to the PYTHONPATH fixes the issue.