You can try this in a terminal:
```
python -c "from unittest.mock import MagicMock; open(MagicMock(), 'w'); print(0)"
```
But why didn't the tests fail under pytest?
pytest wraps, substitutes or otherwise messes with `sys.stdout` enough that fd 1 being dead doesn't cause prints to fail.
The best part? The method that calls `shutil.copy` is called `_safe_copy`, but it doesn't check whether the values it receives are strings or `Path`s. So it happily passes a `MagicMock` along as the copy destination.
So yeah, test your tests, and if you call something safe make it at least careful.
Tests started failing when run with unittest, had been running fine with pytest for a while.
Tests error out with `OSError: [Errno 9] Bad file descriptor`.
Turns out if you `shutil.copy` something onto a `MagicMock`, you kill `sys.stdout`:
```
from unittest.mock import MagicMock
import shutil
m = MagicMock()
m.__fspath__.__index__() # → 1
shutil.copy(filename, m)
[errors omitted]
print(1) # → OSError: [Errno 9] Bad file descriptor
```
Much head scratching!
It depends on what, exactly, you want. time.localtime() will give you a value in the system's configured #timezone. time.gmtime() will give you #UTC. The difference between those will tell you the current local time's offset from UTC.
If you want the name of the configured timezone, on many Unix-type systems, you can read /etc/timezone to get it.
If you want more specific info about a timezone, you can add an external dependency which includes (or provides access to a system-provided) database of timezone info. This stuff changes often, and is decided politically rather than technically, so it's a moving target and the #Python #stdlib doesn't try to include it. `pytz` is one such package with a fairly complete database.
And you can easily override any of these in a test framework. Using unittest.mock.MagicMock(), for example, lets you override any of the above with whatever value you want those functions to return.
danzin
C.