dateutil 2.6 gives segfault in normalizing timestamp with datetutil timezone

[davidslac]

Newly release dateutil 2.6.0 breaks some of the tests related to the use of dateutil timezones (travis is therefore currently failing)

---

Original report:

A small, complete example of the issue

I maintain central installs of miniconda environments that include pandas. My previous environment with pandas 0.19.0, if I did this

python -c "import pandas; pandas.test('fast')"

it worked. Now with pandas 0.19.1, it seg faults. Other packages may have been updated in the new environment.

Below are details - first the failure in my ana-1.0.5 environment, it is clearly segfaulting on a test maybe 2/3 the way through? Then the success in my ana-1.0.4 environment, then the pd.get_versions() in the working old environment, and finally in the newer environment where it fails:

``` (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ python -c "import pandas; pandas.test('fast')" Running unit tests for pandas pandas version 0.19.1 numpy version 1.11.2 pandas is installed in /reg/g/psdm/sw/conda/inst/miniconda2-dev-rhel7/envs/ana-1.0.5/lib/python2.7/site-packages/pandas Python version 2.7.12 |Continuum Analytics, Inc.| (default, Jul 2 2016, 17:42:40) [GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] nose version 1.3.7 /reg/g/psdm/sw/conda/inst/miniconda2-dev-rhel7/envs/ana-1.0.5/lib/python2.7/site-packages/nose/importer.py:94: FutureWarning: The pandas.rpy module is deprecated and will be removed in a future version. We refer to external packages like rpy2. See here for a guide on how to port your code to rpy2: http://pandas.pydata.org/pandas-docs/stable/r_interface.html mod = load_module(part_fqname, fh, filename, desc) ...................................................................................S...........................S.......S.......S.......S.........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................S............SS.....................................................................................................................................................................................................S............SS...S................................................................................................................................................................................S............SS..S...............S...................................S.........S.SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS.SSSSS.S........SS...SS.SS.....................................................................................................................S.......................S......................................................................SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS..SS..................................................S.............................................................................................................................................................................................................................................................................................................................................................S................................................................................S..SS.....SSSSSSSSSSSSSSSSSSSSSSSSSSS....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................S..S...............................................................Segmentation fault (core dumped) (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ python -c "import pandas; pandas.test('fast')" -bash: syntax error near unexpected token `pslogin7a:' (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ Running unit tests for pandas -bash: Running: command not found (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ pandas version 0.19.1 -bash: pandas: command not found (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ numpy version 1.11.2 -bash: numpy: command not found (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ pandas is installed in /reg/g/psdm/sw/conda/inst/miniconda2-dev-rhel7/envs/ana-1.0.5/lib/python2.7/site-packages/pandas -bash: pandas: command not found (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ Python version 2.7.12 |Continuum Analytics, Inc.| (default, Jul 2 2016, 17:42:40) [GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] -bash: syntax error near unexpected token `[GCC' (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ nose version 1.3.7 -bash: nose: command not found (ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ source activate ana-1.0.4 (ana-1.0.4) pslogin7a: ~/rel/slaclab_conda/anarel-test $ python -c "import pandas; pandas.test('fast')" Running unit tests for pandas pandas version 0.19.0 numpy version 1.11.2 pandas is installed in /reg/g/psdm/sw/conda/inst/miniconda2-dev-rhel7/envs/ana-1.0.4/lib/python2.7/site-packages/pandas Python version 2.7.12 |Continuum Analytics, Inc.| (default, Jul 2 2016, 17:42:40) [GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] nose version 1.3.7 /reg/g/psdm/sw/conda/inst/miniconda2-dev-rhel7/envs/ana-1.0.4/lib/python2.7/site-packages/nose/importer.py:94: FutureWarning: The pandas.rpy module is deprecated and will be removed in a future version. We refer to external packages like rpy2. See here for a guide on how to port your code to rpy2: http://pandas.pydata.org/pandas-docs/stable/r_interface.html mod = load_module(part_fqname, fh, filename, desc) ..............................................................................................................S.......S.......S.......S..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................S............SS..................................................................................................................................................................................................S............SS...S.............................................................................................................................................................................S............SS..S...............S...................................S.........S.SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS.SSSSS.S........SS...SS.SS.....................................................................................................................S.......................S......................................................................SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS..SS..................................................S.............................................................................................................................................................................................................................................................................................................................................................S................................................................................S..SS.....SSSSSSSSSSSSSSSSSSSSSSSSSSS..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................S..S.......................................................................................................................................................................................................S..............................................................S...S..............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................S....................................................................................................................................................................................................................................................................................................................SSS.......................................................................................................................................................................................................S.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................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..................................................................................................................................................................................................................S................................................................................................................................................................................................................................................................................................................................................................................................................................................. ---------------------------------------------------------------------- Ran 10625 tests in 701.643s

OK (SKIP=537)
(ana-1.0.4) pslogin7a: ~/rel/slaclab_conda/anarel-test $ python -c "import pandas; pandas.show_versions()"

INSTALLED VERSIONS

commit: None
python: 2.7.12.final.0
python-bits: 64
OS: Linux
OS-release: 3.10.0-327.13.1.el7.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: C
LOCALE: None.None

pandas: 0.19.0
nose: 1.3.7
pip: 8.1.2
setuptools: 27.2.0
Cython: 0.24.1
numpy: 1.11.2
scipy: 0.18.1
statsmodels: None
xarray: 0.8.2
IPython: 5.1.0
sphinx: 1.4.8
patsy: None
dateutil: 2.5.3
pytz: 2016.7
blosc: None
bottleneck: 1.1.0
tables: 3.3.0
numexpr: 2.6.1
matplotlib: 1.5.1
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: 2.8
boto: None
pandas_datareader: None
(ana-1.0.4) pslogin7a: ~/rel/slaclab_conda/anarel-test $ source activate ana-1.0.5
(ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $ python -c "import pandas; pandas.show_versions()"

INSTALLED VERSIONS

commit: None
python: 2.7.12.final.0
python-bits: 64
OS: Linux
OS-release: 3.10.0-327.13.1.el7.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: C
LOCALE: None.None

pandas: 0.19.1
nose: 1.3.7
pip: 9.0.1
setuptools: 27.2.0
Cython: 0.25.1
numpy: 1.11.2
scipy: 0.18.1
statsmodels: None
xarray: 0.8.2
IPython: 5.1.0
sphinx: 1.4.8
patsy: None
dateutil: 2.6.0
pytz: 2016.7
blosc: None
bottleneck: 1.1.0
tables: 3.3.0
numexpr: 2.6.1
matplotlib: 1.5.1
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: 2.8
boto: None
pandas_datareader: None
(ana-1.0.5) pslogin7a: ~/rel/slaclab_conda/anarel-test $

</details>

[jorisvandenbossche]

Can you run the test with verbose mode so you can see for which test it segfaults? pd.test(verbose=10)

[TomAugspurger]

Some of our PR builds are segfaulting as well, e.g. https://travis-ci.org/pandas-dev/pandas/jobs/174412414

No failures on master yet though. Haven't had a chance to dig in yet.

[jorisvandenbossche]

On that PR, it are all the builds using python 3.5 that fail with a segfault

[jorisvandenbossche]

If I compare the installed versions before and after the moment tests started failing, it is dateutil that changed from 2.5.3 to 2.6.0

[jreback]

https://pypi.python.org/pypi/python-dateutil/2.6.0

shocker that this breaks something
they don't have a good history of back compat

[jorisvandenbossche]

OK, small reproducible example:

import pandas as pd
import datetime

dt = datetime.datetime(2011, 1, 1, 9, 0)
offset = pd.offsets.Day()
pd.Timestamp(dt, tz='dateutil/Asia/Tokyo')
pd.Timestamp(dt, tz='dateutil/Asia/Tokyo') + offset
offset2 = pd.offsets.Day(normalize=True)
pd.Timestamp(dt, tz='dateutil/Asia/Tokyo') + offset2

gives

>>> import pandas as pd
>>> import datetime
>>> 
>>> dt = datetime.datetime(2011, 1, 1, 9, 0)
>>> offset = pd.offsets.Day()
>>> pd.Timestamp(dt, tz='dateutil/Asia/Tokyo')
Timestamp('2011-01-01 09:00:00+0900', tz='dateutil//usr/share/zoneinfo/Asia/Tokyo')
>>> pd.Timestamp(dt, tz='dateutil/Asia/Tokyo') + offset
Timestamp('2011-01-02 09:00:00+0900', tz='dateutil//usr/share/zoneinfo/Asia/Tokyo')
>>> offset2 = pd.offsets.Day(normalize=True)
>>> pd.Timestamp(dt, tz='dateutil/Asia/Tokyo') + offset2
Segmentation fault (core dumped)

[jorisvandenbossche]

So, it's related to using their timezones and normalizing offsets, so rather a specific use case that won't affect to much people I think.
Jeff, a lot of people can say the same about pandas :-)

[jorisvandenbossche]

Trimmed down a bit further:

In [1]: dt = pd.Timestamp('2016-01-01 09:00:00', tz='dateutil/Asia/Tokyo')

In [2]: dtpy = dt.to_pydatetime()

In [3]: dtpy
Out[3]: datetime.datetime(2016, 1, 1, 9, 0, tzinfo=tzfile('/usr/share/zoneinfo/Asia/Tokyo'))

In [4]: dtpy.replace(hour=0)
Out[4]: datetime.datetime(2016, 1, 1, 0, 0, tzinfo=tzfile('/usr/share/zoneinfo/Asia/Tokyo'))

In [5]: dt.replace(hour=0)
Segmentation fault (core dumped)

[jreback]

Jeff, a lot of people can say the same about pandas :-)

well maybe though we really really are thoughtful /. try hard /. give notice

[pganssle]

well maybe though we really really are thoughtful /. try hard /. give notice

If you have problems with backwards compatibility, feel free to kick off builds against dateutil's master branch and notify me of issues before a release. It's not like we're changing interfaces willy-nilly and backwards compatibility is essentially an overriding goal of the project, but it's mostly just me working on the project and I can't cross-test against every downstream user or know the weird, undocumented behaviors that apparently people are relying on.

[jreback]

@pganssle

we have been biten by downstream things before (by other deps)
just trying minimize disruptions to upstream

yes we could test against master but that makes our matrix even bigger
in any event this is prob just a small easily correctable issue

[jorisvandenbossche]

@pganssle all respect for your hard work on dateutil! That's why I pointed out to Jeff that people could say the same for pandas, because even when you care about backwards compatibility, it always happen that people are relying on your project in a way you did not expect or don't want to. And that for sure happens in case of pandas as well.

Apart from including dateutil master in our builds (as @jreback said, our test matrix is also already huge), what would also be helpful is getting notified of an upcoming release (not sure if you do a release candidate? or if there is a communication channel for such things? (where there is not too much other noise))

[pganssle]

@jorisvandenbossche I have set up a python-dateutil mailing list, but no one has joined it, so I do not usually announce releases there. Usually I just create a Release issue before at least a major release and tag in it everyone who has submitted an issue or PR that was included in the release and leave that open for a day or so (unless it's a critical bugfix).

I think going forward I'll also announce it on the mailing list (you can join here). At the moment, no one has ever sent a message to it, so I would consider it "low noise".