gcc-backport problem on Debian 9

[David Malcolm]

On Mon, 2020-07-13 at 08:39 +0200, Hans-Peter Nilsson via Gcc wrote:
> Again, Debian 9.  Doing "git gcc-backport a4aca1edaf37d43" on
> releases/gcc-10 gave me:
> 
> [releases/gcc-10 83cf5a7c6a5] PR94600: fix volatile access to the
> whole of a compound object.
>  Date: Sun Jul 5 20:50:52 2020 +0200
>  9 files changed, 276 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-1.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-2.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-3.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-4.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-5.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-6.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-7.c
>  create mode 100644 gcc/testsuite/gcc.dg/pr94600-8.c
> Traceback (most recent call last):
>   File "/mnt/storage1/hp/autotest/gccgit/gcc/contrib/git-
> backport.py", line 34, in <module>
>     changelogs = subprocess.check_output(cmd, shell=True,
> encoding='utf8')
>   File "/usr/lib/python3.5/subprocess.py", line 316, in check_output
>     **kwargs).stdout
>   File "/usr/lib/python3.5/subprocess.py", line 383, in run
>     with Popen(*popenargs, **kwargs) as process:
> TypeError: __init__() got an unexpected keyword argument 'encoding'

This is subprocess.Popen.__init__, which is part of the Python standard
library.

https://docs.python.org/3.6/library/subprocess.html#popen-constructor
states:
  "New in version 3.6: 'encoding' and 'errors' were added."

Hence it looks like git-backport.py is implicitly assuming Python 3.6
or later.


> The commit looked fine with a "(cherry picked from commit
> a4aca1edaf37d43b2b7e9111825837a7a317b1b0)", appended to the
> commit log, so I pushed it successfully (using git am on the
> format-patch of this commit on another machine, so the sha above
> is not the final one, but 6f49c66ed4e060c333d8bcd).
> 
> Not sure what other information is needed, but maybe:
> 
> $ dpkg -s python3
> Package: python3
> Status: install ok installed
> Priority: optional
> Section: python
> Installed-Size: 67
> Maintainer: Matthias Klose <doko@debian.org>
> Architecture: amd64
> Multi-Arch: allowed
> Source: python3-defaults
> Version: 3.5.3-1
> Replaces: python3-minimal (<< 3.1.2-2)
> Provides: python3-profiler
> Depends: python3.5 (>= 3.5.3-1~), libpython3-stdlib (= 3.5.3-1), dh-
> python
> Pre-Depends: python3-minimal (= 3.5.3-1)
> Suggests: python3-doc (>= 3.5.3-1), python3-tk (>= 3.5.3-1~),
> python3-venv (>= 3.5.3-1)
> Description: interactive high-level object-oriented language (default
> python3 version)
>  Python, the high-level, interactive object oriented language,
>  includes an extensive class library with lots of goodies for
>  network programming, system administration, sounds and graphics.
>  .
>  This package is a dependency package, which depends on Debian's
> default
>  Python 3 version (currently v3.5).
> Homepage: http://www.python.org/
> 
> FWIW, I manually did "apt-get install python3-unidiff" and
> "apt-get install python3-dateutil" to deal with missing packages
> in other related scripts.  Perhaps this is a different
> incantation.  Are the dependencies listed somewhere?
> 
> brgds, H-P
>