[New-bugs-announce] [issue31298] Error when calling numpy.astype

[Daniel]

New submission from Daniel:

Ubuntu 16.04.3
Python 3.5.2
Numpy version 1.11.0

Running the following two commands causes Python to crash:
import numpy as np
np.array([[1, 2],[3,4]]).astype(np.dtype([("a", np.float), ("b", np.str_)]))

The error occurs when running in an interactive session and when running those two commands as a script.

The error I get is:
*** Error in `python3': free(): invalid next size (normal): 0x0000000001a088f0 ***

A memory map printed after the error is attached.

The backtrace is
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7f55ac35e7e5]
/lib/x86_64-linux-gnu/libc.so.6(+0x8037a)[0x7f55ac36737a]
/lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7f55ac36b53c]
/usr/lib/python3/dist-packages/numpy/core/multiarray.cpython-35m-x86_64-linux-gnu.so(+0x6d35e)[0x7f55ab0fa35e]
/usr/lib/python3/dist-packages/numpy/core/multiarray.cpython-35m-x86_64-linux-gnu.so(+0x45a29)[0x7f55ab0d2a29]
/usr/lib/python3/dist-packages/numpy/core/multiarray.cpython-35m-x86_64-linux-gnu.so(+0x461a2)[0x7f55ab0d31a2]
/usr/lib/python3/dist-packages/numpy/core/multiarray.cpython-35m-x86_64-linux-gnu.so(+0xcf828)[0x7f55ab15c828]
python3(PyCFunction_Call+0x77)[0x4e9bc7]
python3(PyEval_EvalFrameEx+0x614)[0x524414]
python3[0x52d2e3]
python3(PyEval_EvalCode+0x1f)[0x52dfdf]
python3[0x5fd2c2]
python3(PyRun_FileExFlags+0x9a)[0x5ff76a]
python3(PyRun_SimpleFileExFlags+0x1bc)[0x5ff95c]
python3(Py_Main+0x456)[0x63e7d6]
python3(main+0xe1)[0x4cfe41]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f55ac307830]
python3(_start+0x29)[0x5d5f29]

----------
components: Interpreter Core
files: memdump.txt
messages: 300970
nosy: droth
priority: normal
severity: normal
status: open
title: Error when calling numpy.astype
type: crash
versions: Python 3.5
Added file: http://bugs.python.org/file47105/memdump.txt

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue31298>
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