Error Message: "make sure the Graphviz executables are on your systems' PATH"

[csala]

• SDV version: 0.4.0

Description

SDV depends on graphviz to visualize Metadata. The graphviz dependency has been properly set in the setup.py requirements, but graphviz binaries need to also be installed in the system:

A warning about this should be added in the README and the code should capture the exception and raise a new one providing more precise details about the origin of the error and how to fix it:

• On Debian-based systems: sudo apt install graphviz
• On Mac systems: brew install graphviz

Reproducing the error

The error occurs any time the metadata.visualize() method is called within a jupyter Notebook in a system which is missing the graphviz binaries.

This is the error shown:

---------------------------------------------------------------------------
FileNotFoundError                         Traceback (most recent call last)
~/.virtualenvs/SDV/lib/python3.6/site-packages/graphviz/backend.py in run(cmd, input, capture_output, check, encoding, quiet, **kwargs)
    163     try:
--> 164         proc = subprocess.Popen(cmd, startupinfo=get_startupinfo(), **kwargs)
    165     except OSError as e:

/usr/lib/python3.6/subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds, encoding, errors)
    728                                 errread, errwrite,
--> 729                                 restore_signals, start_new_session)
    730         except:

/usr/lib/python3.6/subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite, restore_signals, start_new_session)
   1363                             err_msg += ': ' + repr(err_filename)
-> 1364                     raise child_exception_type(errno_num, err_msg, err_filename)
   1365                 raise child_exception_type(err_msg)

FileNotFoundError: [Errno 2] No such file or directory: 'dot': 'dot'

During handling of the above exception, another exception occurred:

ExecutableNotFound                        Traceback (most recent call last)
~/.virtualenvs/SDV/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    343             method = get_real_method(obj, self.print_method)
    344             if method is not None:
--> 345                 return method()
    346             return None
    347         else:

~/.virtualenvs/SDV/lib/python3.6/site-packages/graphviz/files.py in _repr_svg_(self)
    111 
    112     def _repr_svg_(self):
--> 113         return self.pipe(format='svg').decode(self._encoding)
    114 
    115     def pipe(self, format=None, renderer=None, formatter=None, quiet=False):

~/.virtualenvs/SDV/lib/python3.6/site-packages/graphviz/files.py in pipe(self, format, renderer, formatter, quiet)
    136         out = backend.pipe(self._engine, format, data,
    137                            renderer=renderer, formatter=formatter,
--> 138                            quiet=quiet)
    139 
    140         return out

~/.virtualenvs/SDV/lib/python3.6/site-packages/graphviz/backend.py in pipe(engine, format, data, renderer, formatter, quiet)
    242     """
    243     cmd, _ = command(engine, format, None, renderer, formatter)
--> 244     out, _ = run(cmd, input=data, capture_output=True, check=True, quiet=quiet)
    245     return out
    246 

~/.virtualenvs/SDV/lib/python3.6/site-packages/graphviz/backend.py in run(cmd, input, capture_output, check, encoding, quiet, **kwargs)
    165     except OSError as e:
    166         if e.errno == errno.ENOENT:
--> 167             raise ExecutableNotFound(cmd)
    168         else:
    169             raise

ExecutableNotFound: failed to execute ['dot', '-Tsvg'], make sure the Graphviz executables are on your systems' PATH

[JagdishKolhe]

This is definitely the installation issue of graphviz. I would recommend to verify the path in the terminal where you are visualizing. sudo. I dont get such error on Google Colab.

More information at
https://stackoverflow.com/questions/35064304/runtimeerror-make-sure-the-graphviz-executables-are-on-your-systems-path-aft

[csala]

The exception seems to be raised directly from within IPython core, so we cannot actually catch it to improve the error message.

We will add a runtime warning and notes in the README/tutorials pointing at the Graphviz installation page.