pip install 給出“TypeError：‘int’對像不可迭代”

在Debian Stretch中，當我嘗試通過安裝 python 包 python-constraint

pip install python-constraint

我收到以下錯誤；

Exception:
Traceback (most recent call last):
 File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
   status = self.run(options, args)
 File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 290, in run
   requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
 File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1178, in prepare_files
   url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
 File "/usr/lib/python2.7/dist-packages/pip/index.py", line 292, in find_requirement
   elif is_prerelease(version) and not (self.allow_all_prereleases or req.prereleases):
 File "/usr/lib/python2.7/dist-packages/pip/util.py", line 739, in is_prerelease
   return any([any([y in set(["a", "b", "c", "rc", "dev"]) for y in x]) for x in parsed])
TypeError: 'int' object is not iterable

Storing debug log for failure in /home/von/.pip/pip.log

在Debian Jessie中，同樣的命令是成功的。

哪裡有問題？如何解決？

$python --version
Python 2.7.9

$pip --version
pip 1.5.6 from /usr/lib/python2.7/dist-packages (python 2.7)

該錯誤與錯誤有關https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=786580

解決方案是降級python-distlib並python-distlib-whl到 jessie 版本。

wget http://ftp.debian.org/debian/pool/main/d/distlib/python-distlib_0.1.9-1_all.deb
wget http://ftp.debian.org/debian/pool/main/d/distlib/python-distlib-whl_0.1.9-1_all.deb
dpkg -i python-distlib_0.1.9-1_all.deb 
dpkg -i python-distlib-whl_0.1.9-1_all.deb 

之後執行pip install就成功了。

$ sudo pip install python-constraint
Downloading/unpacking python-constraint
 Downloading python-constraint-1.2.tar.bz2
 Running setup.py (path:/tmp/pip-build-JeOIzg/python-constraint/setup.py) egg_info for package python-constraint

Installing collected packages: python-constraint
 Running setup.py install for python-constraint

Successfully installed python-constraint
Cleaning up...

將軟體包擱置，等待官方的錯誤修復。

sudo aptitude hold python-distlib python-distlib-whl

引用自：https://unix.stackexchange.com/questions/206121