[2.8.1] Tests depend on the "python" executable name

[olebole]

When running the tests on a standard Debian machine, I get a lot of errors like

______________________ test_asdf_open_failure[version4] _______________________
tmp_path = PosixPath('/tmp/pytest-of-debci/pytest-0/test_asdf_open_failure_version4')
create_editor = <function create_editor.<locals>._create_editor at 0x7f502e72d040>
version = AsdfVersion('1.4.0')
mock_input = <function mock_input.<locals>._mock_input at 0x7f502e72dca0>
    def test_asdf_open_failure(tmp_path, create_editor, version, mock_input):
        file_path = str(tmp_path/"test.asdf")
    
        with asdf.AsdfFile(version=version) as af:
            af["foo"] = "bar"
            af.write_to(file_path)
    
        os.environ["EDITOR"] = create_editor(r"^#ASDF .*?$", "#HJKL 1.0.0")
    
        with file_not_modified(file_path):
            with mock_input(r"\(c\)ontinue editing or \(a\)bort\?", "a"):
>               assert main.main_from_args(["edit", file_path]) == 1
/usr/lib/python3/dist-packages/asdf/commands/tests/test_edit.py:311: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/lib/python3/dist-packages/asdf/commands/main.py:70: in main_from_args
    result = args.func(args)
/usr/lib/python3/dist-packages/asdf/commands/edit.py:62: in run
    return edit(args.filename)
/usr/lib/python3/dist-packages/asdf/commands/edit.py:213: in edit
    open_editor(temp_file.name)
/usr/lib/python3/dist-packages/asdf/commands/edit.py:372: in open_editor
    subprocess.run(f"{editor} {path}", check=True, shell=True) # nosec
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
input = None, capture_output = False, timeout = None, check = True
popenargs = ('python /tmp/pytest-of-debci/pytest-0/test_asdf_open_failure_version4/editor.py /tmp/test-_h78phud.yaml',)
kwargs = {'shell': True}
process = <Popen: returncode: 127 args: ['p', 'y', 't', 'h', 'o', 'n', ' ', '/', 't', ...>
stdout = None, stderr = None, retcode = 127
    def run(*popenargs,
            input=None, capture_output=False, timeout=None, check=False, **kwargs):
        """…"""
        …    
        with Popen(*popenargs, **kwargs) as process:
            try:
                stdout, stderr = process.communicate(input, timeout=timeout)
            except TimeoutExpired as exc:
                process.kill()
                if _mswindows:
                    # …
                    exc.stdout, exc.stderr = process.communicate()
                else:
                    # …
                    process.wait()
                raise
            except:  # Including KeyboardInterrupt, communicate handled that.
                process.kill()
                # We don't call process.wait() as .__exit__ does that for us.
                raise
            retcode = process.poll()
            if check and retcode:
>               raise CalledProcessError(retcode, process.args,
                                         output=stdout, stderr=stderr)
E               subprocess.CalledProcessError: Command 'python /tmp/pytest-of-debci/pytest-0/test_asdf_open_failure_version4/editor.py /tmp/test-_h78phud.yaml' returned non-zero exit status 127.
/usr/lib/python3.9/subprocess.py:528: CalledProcessError
----------------------------- Captured stderr call -----------------------------
/bin/sh: 1: python: not found

The default Python executable on Debian machines is always "python3", which is IMO the standard and always supported.

[eslavich]

Oops, thanks! We'll get that fixed in the next patch to 2.8.