Make exceptions less verbose by default

[ricardoV94]

PyTensor exceptions are very verbose by default. Users often struggle to even find the actual error message.

This PR makes exceptions more minimal with a hint to set the relevant flag exception_verbosity to medium (the old low or high) for more details.

The type error in the following snippet:

import pytensor
import pytensor.tensor as pt

x = pt.matrix("x")
y = pt.specify_shape(x, (2, 3))
fn = pytensor.function([x], y, mode="FAST_RUN")

fn([1])

Now looks like:

Traceback (most recent call last):
  File "/home/ricardo/miniforge3/envs/pytensor-dev/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-2-6c9f1f34f2ad>", line 8, in <module>
    fn([1])
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 960, in __call__
    arg_container.storage[0] = arg_container.type.filter(
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ricardo/Documents/pytensor/pytensor/tensor/type.py", line 254, in filter
    raise TypeError(
TypeError: Wrong number of dimensions: expected 2, got 1 with shape (1,).
Invalid argument to PyTensor function at index 0.

Whereas with the old default looked like

Traceback (most recent call last):
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-3-6c9f1f34f2ad>", line 8, in <module>
    fn([1])
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 944, in __call__
    arg_container.storage[0] = arg_container.type.filter(
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/ricardo/Documents/pytensor/pytensor/tensor/type.py", line 242, in filter
    raise TypeError(
TypeError: Bad input argument to pytensor function with name "<ipython-input-3-6c9f1f34f2ad>:6" at index 0 (0-based).  

Backtrace when that variable is created:
  File "/app/extra/plugins/python-ce/helpers/pydev/_pydev_bundle/pydev_ipython_console_011.py", line 438, in add_exec
    res = self.ipython.run_cell(line, store_history=True)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3075, in run_cell
    result = self._run_cell(
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3130, in _run_cell
    result = runner(coro)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/async_helpers.py", line 128, in _pseudo_sync_runner
    coro.send(None)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3334, in run_cell_async
    has_raised = await self.run_ast_nodes(code_ast.body, cell_name,
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3517, in run_ast_nodes
    if await self.run_code(code, result, async_=asy):
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-3-6c9f1f34f2ad>", line 4, in <module>
    x = pt.matrix("x")
Wrong number of dimensions: expected 2, got 1 with shape (1,).

A runtime error:

fn([[1]])

Now looks like this

Traceback (most recent call last):
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-8-df63f13088e4>", line 8, in <module>
    fn([[1]])
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 1040, in __call__
    raise_with_op(
  File "/home/ricardo/Documents/pytensor/pytensor/link/utils.py", line 320, in raise_with_op
    raise exc_value.with_traceback(exc_trace)
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 1030, in __call__
    outputs = vm() if output_subset is None else vm(output_subset=output_subset)
              ^^^^
AssertionError: SpecifyShape: dim 0 of input has shape 1, expected 2.

HINT: Set PyTensor `config.exception_verbosity` to `medium` or `high` for more information about the source of the error.

Whereas before it looked like

Traceback (most recent call last):
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 1037, in __call__
    outputs = vm() if output_subset is None else vm(output_subset=output_subset)
              ^^^^
AssertionError: SpecifyShape: dim 0 of input has shape 1, expected 2.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-2-df63f13088e4>", line 8, in <module>
    fn([[1]])
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 1047, in __call__
    raise_with_op(
  File "/home/ricardo/Documents/pytensor/pytensor/link/utils.py", line 526, in raise_with_op
    raise exc_value.with_traceback(exc_trace)
  File "/home/ricardo/Documents/pytensor/pytensor/compile/function/types.py", line 1037, in __call__
    outputs = vm() if output_subset is None else vm(output_subset=output_subset)
              ^^^^
AssertionError: SpecifyShape: dim 0 of input has shape 1, expected 2.
Apply node that caused the error: SpecifyShape(x, 2, 3)
Toposort index: 0
Inputs types: [TensorType(float64, shape=(None, None)), TensorType(int8, shape=()), TensorType(int8, shape=())]
Inputs shapes: [(1, 1), (), ()]
Inputs strides: [(8, 8), (), ()]
Inputs values: [array([[1.]]), array(2, dtype=int8), array(3, dtype=int8)]
Outputs clients: [[DeepCopyOp(SpecifyShape.0)]]

Backtrace when the node is created (use PyTensor flag traceback__limit=N to make it longer):
  File "/app/extra/plugins/python-ce/helpers/pydev/_pydev_bundle/pydev_ipython_console_011.py", line 438, in add_exec
    res = self.ipython.run_cell(line, store_history=True)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3075, in run_cell
    result = self._run_cell(
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3130, in _run_cell
    result = runner(coro)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/async_helpers.py", line 128, in _pseudo_sync_runner
    coro.send(None)
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3334, in run_cell_async
    has_raised = await self.run_ast_nodes(code_ast.body, cell_name,
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3517, in run_ast_nodes
    if await self.run_code(code, result, async_=asy):
  File "/home/ricardo/miniforge3/envs/pytensor/lib/python3.12/site-packages/IPython/core/interactiveshell.py", line 3577, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-2-df63f13088e4>", line 5, in <module>
    y = pt.specify_shape(x, (2, 3))

HINT: Use the PyTensor flag `exception_verbosity=high` for a debug print-out and storage map footprint of this Apply node.

---

📚 Documentation preview 📚: https://pytensor--1330.org.readthedocs.build/en/1330/

[ricardoV94]

The add_note feature was only added in 3.11, so I would wait

[Copilot]

Pull Request Overview

This PR simplifies PyTensor exception messages by reducing their verbosity by default, making it easier for users to find the actual error message. The changes introduce a new "low" verbosity level that shows minimal information with a hint to increase verbosity for more details.

• Adds a new "low" exception verbosity level as the default
• Simplifies error message formatting in function calls
• Provides hints to users about how to get more detailed error information

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
pytensor/link/utils.py	Adds hint message for low verbosity exceptions
pytensor/configdefaults.py	Updates exception verbosity config to include new "medium" level and simplified description
pytensor/compile/function/types.py	Refactors exception handling to use cleaner messages and respect verbosity settings

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[Copilot]

Pull Request Overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

---

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[ricardoV94]

Failing jax test addressed in #1646