grass.script: Always use env for shutil.which

[wenzeslaus]

Currently, shutil.which is called on Windows to find the executable. However, it does not use the provided env (if any) which leads to the executable not being find if only the env parameter for run_command (and family) contains the runtime setup. This is not a problem on Linux (and probably unix/posix in general), because the Popen call eventually uses the system to find the executable and uses the provided env. However, on Windows, env is not used by the subprocess call. The shutil.which uses the os.environ process, so when the global environment is used, everything still works even on Windows.

This adds the PATH from env to the shutil.which call if it is there, so that it is used to find the exectuable. Additionally, this adds the shutil.which call for all platforms which is considered a best practice, avoiding Bandit's B607: Test for starting a process with a partial path.

https://bandit.readthedocs.io/en/latest/plugins/b607_start_process_with_partial_path.html

[echoix]

Do you have an idea on what to use to test it? I'll try it locally, but I don't have an idea in mind

[wenzeslaus]

On Windows, calling create_project before grass.script.setup.init presumably fails on main and in 8.4 with g.proj not found while on Linux it works.

[landam]

@wenzeslaus I run the script below from OSGeo4W shell:

import os
import sys
import subprocess

# Append GRASS to the python system path
sys.path.append(
    subprocess.check_output(["grass84.bat", "--config", "python_path"], text=True).strip()
)

import grass.script as gs

# Create a new project
project_path = os.path.join(os.environ["HOMEPATH"], "Documents", "grassdata", "pytest")
gs.create_project(path=project_path, epsg="3358")

# Initialize the GRASS session
with gs.setup.init(project_path) as session:
    # Run GRASS tools
    gs.run_command("g.region", flags="p")

It still fails with an error:

Traceback (most recent call last):
  File "c:\Users\martin\Downloads\grass_create_project.py", line 15, in <module>
    gs.create_project(path=project_path, epsg="3358")
  File "C:\OSGeo4W\apps\grass\grass84\etc\python\grass\script\core.py", line 1820, in create_project
    ps = pipe_command(
         ^^^^^^^^^^^^^
  File "C:\OSGeo4W\apps\grass\grass84\etc\python\grass\script\core.py", line 513, in pipe_command
    return start_command(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\OSGeo4W\apps\grass\grass84\etc\python\grass\script\core.py", line 434, in start_command
    return Popen(args, **popts)
           ^^^^^^^^^^^^^^^^^^^^
  File "C:\OSGeo4W\apps\grass\grass84\etc\python\grass\script\core.py", line 56, in __init__
    raise OSError(_("Cannot find the executable {0}").format(args[0]))
OSError: Cannot find the executable g.proj

because the path doesn't contain in my case C:\OSGeo4W\apps\grass84\bin:

C:\OSGeo4W\apps\qt5\bin;C:\OSGeo4W\apps\Python312\Scripts;C:\OSGeo4W\bin;C:\Windows\system32;C:\Windows;C:\Windows\system32\WBem

[landam]

@wenzeslaus I tested it on GRASS 8.5 (a6b8391) with the same result.

[wenzeslaus]

Does the OSGeo shell set GISBASE? If yes, that would skip the runtime env setup, and thus fail later.

[wenzeslaus]

Is there a way you could transfer your local test to CI? ie it would fail on current main, but would be disabled, or edit this branch.