Unable to setup virtualenv with '--always-copy' flag due to Errno 1

问题

I am trying to run this command

$ virtualenv --always-copy venv

Then I got all these errors:

        shutil.Error: [('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Drag.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Drag.so', "[Errno 1] Operation not permitted:
 '/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Drag.so'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Ctl.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Ctl.so', "[Errno 1] Operation not permitted: 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Ctl.so'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/imageop.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/imageop.so', "[Errno 1] Operation not permitted: 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/imageop.so'"), 
('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Scrap.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Scrap.so', "[Errno 1] Operation not permitted: 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_Scrap.so'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_testcapi.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_testcapi.so', "[Errno 1] Operation not permitted: 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/_testcapi.so'"), 
('/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/unicodedata.so', 
'/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/unicodedata.so', "[Errno 1] Operation not permitted: '/Users/antkong/dev/zeetings/venv/lib/python2.7/lib-dynload/unicodedata.so'"),

I checked the permission of the source file. It is all readable

$ ls -l '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Drag.so'
-rwxr-xr-x  1 root  wheel  55936  3 Oct 16:50 /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Drag.so

I have always ensured venv does not exist before running the command.

So why the failure?

Version info:

$ python --version
Python 2.7.10
$ pip --version
pip 9.0.1 from /Library/Python/2.7/site-packages (python 2.7)

回答1:

virtualenv use shutil.copytree to copy files, copytree will copy src file flags to destination with copystat, but the macOS system python files have a special flag 0x80000, which can not set by a normal user, even root.

if you installed a python with homebrew, which does not have this flag, this command would work.

---

Update:

according to stat.h 0x80000 is SF_RESTRICTED:

#define SF_RESTRICTED   0x00080000  /* restricted access */

it is something new with Yosemite System Integrity Protection.

you could see restricted flag in with ls -lO output:

$ ls -lO '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Drag.so'
-rwxr-xr-x  1 root  wheel  restricted,compressed 55888 Jul 15 12:21 /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/_Drag.so

if you try to set it in the command line:

$ sudo chflags restricted tmp
chflags: tmp: Operation not permitted

I think python shutil.copystat should exclude this flag as there is no way to set it in userland without special entitlement assigned by Apple.

来源：https://stackoverflow.com/questions/46781050/unable-to-setup-virtualenv-with-always-copy-flag-due-to-errno-1