I tried to run the downward lab by following the tutorial given in the page "https://lab.readthedocs.io/en/stable/downward.tutorial.html". The first step build is performed successfully but after that the next steps like run, fetch show some unexplained error(as following).
Traceback (most recent call last):
File "/home/user/downward-projects/downward/experiments/cg-vs-ff/data/2020-09-11-A-cg-vs-ff/runs-00001-00100/00002/../../code-993edc3d7952b45a9ef691695d5fb4492dc322c4_e5e41175/fast-downward.py", line 5, in <module>
main()
File "/home/user/downward-projects/downward/experiments/cg-vs-ff/data/2020-09-11-A-cg-vs-ff/code-993edc3d7952b45a9ef691695d5fb4492dc322c4_e5e41175/driver/main.py", line 39, in main
(exitcode, continue_execution) = run_components.run_translate(args)
File "/home/user/downward-projects/downward/experiments/cg-vs-ff/data/2020-09-11-A-cg-vs-ff/code-993edc3d7952b45a9ef691695d5fb4492dc322c4_e5e41175/driver/run_components.py", line 60, in run_translate
stderr, returncode = call.get_error_output_and_returncode(
File "/home/user/downward-projects/downward/experiments/cg-vs-ff/data/2020-09-11-A-cg-vs-ff/code-993edc3d7952b45a9ef691695d5fb4492dc322c4_e5e41175/driver/call.py", line 68, in get_error_output_and_returncode
p = subprocess.Popen(cmd, preexec_fn=preexec_fn, stderr=subprocess.PIPE)
File "/usr/lib/python3.10/subprocess.py", line 966, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/usr/lib/python3.10/subprocess.py", line 1843, in _execute_child
raise child_exception_type(err_msg)
subprocess.SubprocessError: Exception occurred in preexec_fn.