classification
Title: Availability of utimensat, futimens not checked correctly on macOS
Type: crash Stage:
Components: Cross-Build Versions: Python 3.7, Python 3.6, Python 3.5
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: Alex.Willmer, Peter Petrik, Peter Petrik2, indygreg, jmr, ned.deily, ronaldoussoren
Priority: normal Keywords:

Created on 2017-09-27 06:23 by jmr, last changed 2019-08-13 09:42 by ronaldoussoren.

Messages (6)
msg303098 - (view) Author: Joshua Root (jmr) Date: 2017-09-27 06:23
The futimens and utimensat functions are available in High Sierra but not previous versions of macOS. Building against the 10.13 SDK and deploying to an earlier version will result in a crash when the dynamic linker can't find the symbols at runtime. Availability of the symbols needs to be checked at runtime before use.

This was originally reported in <https://trac.macports.org/ticket/54893>.
msg303386 - (view) Author: Ronald Oussoren (ronaldoussoren) * (Python committer) Date: 2017-09-30 02:06
This is true for other symbols as well, when deploying to older releases of macOS. 

I have added runtime checking for a number of symbols in the past, that could be extended to newer APIs.  

--
On the road, hence brief. 

Op 30 sep. 2017 om 09:17 heeft Terry J. Reedy <report@bugs.python.org> het volgende geschreven:

> 
> Change by Terry J. Reedy <tjreedy@udel.edu>:
> 
> 
> ----------
> components: +macOS
> nosy: +ned.deily, ronaldoussoren
> title: Availability of utimensat and futimens not checked correctly on macOS -> Availability of utimensat,futimens not checked correctly on macOS
> 
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue31601>
> _______________________________________
msg330010 - (view) Author: Joshua Root (jmr) Date: 2018-11-16 19:06
This isn't just a cross-build issue, or rather (depending on how you look at it) cross-builds are increasingly the norm due to Apple only providing a newer SDK on older OS versions. For example the latest version of Xcode available for 10.12 only comes with the 10.13 SDK.
msg330122 - (view) Author: Peter Petrik (Peter Petrik2) Date: 2018-11-20 07:34
This issue blocks QGIS distribution on MacOS for 10.11 and 10.12 releases, https://github.com/lutraconsulting/qgis-mac-packager/issues/22

I would like to know how much work is involved to fix the issue, possible whether there is a plan to fix it. Also we would appreciate quote & timeline for fix to info@lutraconsulting.co.uk, so we can consider to sponsor this fix. Thanks
msg349515 - (view) Author: Gregory Szorc (indygreg) * Date: 2019-08-13 03:52
I ran into this with PyOxidizer. CPython's `configure` needs to be made aware of the current macOS SDK version and filter out symbols not present in the target macOS version. I worked around it by `undef`'ing some entries from the generated `pyconfig.h` file.

macOS's clang does emit some warnings when it sees symbols that shouldn't be used with the current target version. CPython's build system should consider adding -Werror=unguarded-availability-new to CFLAGS to turn these warnings into errors so they are caught at compile time and not run time. But there should be proper filtering of affected symbols first, otherwise people won't be able to build CPython when targeting older macOS versions.
msg349537 - (view) Author: Ronald Oussoren (ronaldoussoren) * (Python committer) Date: 2019-08-13 09:42
I'd prefer a solution that uses symbols where the are available (weak linking). 

That way users on newer systems can use all functionality available there, without having multiple binaries.

I've done this in the past for older macOS versions, but don't know how involved such patches would be for current versions of CPython.
History
Date User Action Args
2019-08-13 09:42:12ronaldoussorensetmessages: + msg349537
2019-08-13 03:52:12indygregsetnosy: + indygreg
messages: + msg349515
2018-11-20 07:34:55Peter Petrik2setnosy: + Peter Petrik2
messages: + msg330122
2018-11-16 19:06:01jmrsetmessages: + msg330010
2018-11-16 08:07:25Peter Petriksetnosy: + Peter Petrik, Alex.Willmer

components: + Cross-Build, - Build, macOS
versions: + Python 3.7
2017-09-30 02:06:52ronaldoussorensetmessages: + msg303386
title: Availability of utimensat,futimens not checked correctly on macOS -> Availability of utimensat, futimens not checked correctly on macOS
2017-09-30 00:17:18terry.reedysetnosy: + ronaldoussoren, ned.deily

components: + macOS
title: Availability of utimensat and futimens not checked correctly on macOS -> Availability of utimensat,futimens not checked correctly on macOS
2017-09-27 06:23:40jmrcreate