Exits with status code 1 even though it was successful

[sigmavirus24]

Your Environment

Thank you for taking the time to report an issue.

To more efficiently resolve this issue, we'd like to know some basic information about your system and setup.

1. Your operating system: Fedora 28

2. Version of python you are running: 2.7.15

python --version

3. How did you install twine? Did you use your operating system's package manager or pip or something else?

Using pip inside of tox

4. Version of twine you have installed (include complete output of):

twine --version

1.12.0

5. Which package repository are you targeting?

PyPI

If you're having issues uploading a specific package, you must include a copy of the following:

• The package's PKG-INFO file
• A redacted version of your .pypirc file (REMOVE ALL USERNAMES & PASSWORDS BEFORE UPLOADING)

The Issue

Please describe the issue that you are experiencing.

While releasing twine this morning, it claims to have failed even though it very clearly succeeded. I suspect this is a result of a change made in recent weeks.

❯❯❯ tox -e release
GLOB sdist-make: /home/sigmavirus24/sandbox/pypa/twine/setup.py
release create: /home/sigmavirus24/sandbox/pypa/twine/.tox/release
release installdeps: ., wheel
release inst: /home/sigmavirus24/sandbox/pypa/twine/.tox/dist/twine-1.12.0.zip
release installed: bleach==2.1.4,certifi==2018.8.24,cffi==1.11.5,chardet==3.0.4,cmarkgfm==0.4.2,docutils==0.14,future==0.16.0,html5lib==1.0.1,idna==2.7,pkginfo==1.4.2,pycparser==2.19,Pygments==2.2.0,readme-renderer==22.0,requests==2.19.1,requests-toolbelt==0.8.0,six==1.11.0,tqdm==4.26.0,twine==1.12.0,urllib3==1.23,webencodings==0.5.1                                                                                                              
release runtests: PYTHONHASHSEED='1297153739'
release runtests: commands[0] | python setup.py -q bdist_wheel sdist
no previously-included directories found matching '*.yml'
release runtests: commands[1] | twine upload --skip-existing 'dist/*'
Enter your username: 
Enter your password:
Uploading distributions to https://upload.pypi.org/legacy/
  Skipping twine-1.9.1-py2.py3-none-any.whl because it appears to already exist
  Skipping twine-1.9.0-py2.py3-none-any.whl because it appears to already exist
Uploading twine-1.12.0-py2.py3-none-any.whl
100%|█████████████████████████████████████████████████████████████████████| 52.9k/52.9k [00:01<00:00, 31.5kB/s]
  Skipping twine-1.9.1.tar.gz because it appears to already exist
  Skipping twine-1.9.0.tar.gz because it appears to already exist
Uploading twine-1.12.0.tar.gz
100%|█████████████████████████████████████████████████████████████████████| 86.3k/86.3k [00:01<00:00, 62.1kB/s]
ERROR: InvocationError for command '/home/sigmavirus24/sandbox/pypa/twine/.tox/release/bin/twine upload --skip-existing dist/*' (exited with code 1)                                                                              
___________________________________________________ summary ___________________________________________________
ERROR:   release: commands failed

Steps to Reproduce

If the issue is predictable and consistently reproducible, please list the steps here.

[sigmavirus24]

Once fixed, this should be immediately released as 1.12.1