The (from versions: ) is a big clue. It comes from this line in the pip source code. The fact that nothing comes after versions: implies that pip couldn't find any version of djanto-rest-auth in the pypi index. Never mind the version that your requirements.txt asks for. That check comes later.
Here is what versions: should look like when you try to install something that can't be found:
> pip install django-rest-auth==29.42 # ridiculous version that won't be found
Error: Could not find a version that satisfies the requirement django-rest-auth==29.42
(from versions: 0.9.4.macosx-10.14-intel, 0.1, 0.2, 0.2.1, 0.2.2, 0.2.3, 0.2.4,
0.2.5, 0.3.0, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.4.0, 0.5.0, 0.6.0, 0.7.0, 0.8.0,
0.8.1, 0.8.2, 0.9.0, 0.9.1, 0.9.2, 0.9.3, 0.9.5)
The only way versions: can be blank is if the routine find_all_candidates returns an empty list. find-all-candidates ought to return a list with every version of the package that has been released on pypi.org.
I don't know why that routine randomly returns an empty list on your CI box, but I have a hunch it involves the code that scrapes https://pypi.org/simple/django-rest-auth/ for links. Perhaps it is getting back an empty HTML page every once in a while.
Here are some things you can do to debug
- Run pip with the
--verbose flag. This activates some logging of URLs
and links that might be helpful.
- ssh into your CI server and find
site-packages/pip/_internal/index.py. Edit it and add more logging to help you debug. I would start by logging the HTML content that it gets back from pypi.org.
- if you get lucky and find a way to repeat the problem, use
pdb to debug pip on your CI server.
Here is an example of the extra logging you get with --verbose. Really curious what this looks like when your glitch happens:
Collecting django-rest-auth==29.42
-------------------------------------------------------
1 location(s) to search for versions of django-rest-auth:
* https://pypi.org/simple/django-rest-auth/
Getting page https://pypi.org/simple/django-rest-auth/
Looking up "https://pypi.org/simple/django-rest-auth/" in the cache
Request header has "max_age" as 0, cache bypassed
Starting new HTTPS connection (1): pypi.org:443
https://pypi.org:443 "GET /simple/django-rest-auth/ HTTP/1.1" 200 2467
Updating cache with response from "https://pypi.org/simple/django-rest-auth/"
Caching due to etag
Analyzing links from page https://pypi.org/simple/django-rest-auth/
Found link https://files.pythonhosted.org/packages/c8/ff/cffe8cb7961a1665f20115adb035d23a6b1cb08a2a6c1d6de802b13cdcc9/django-rest-auth-0.1.tar.gz#sha256=fcb9feced7f066c92a5f29f2930609316095a7abe3806e09c3d63c36c3607780 (from https://pypi.org/simple/django-rest-auth/), version: 0.1
Found link https://files.pythonhosted.org/packages/af/d2/5d37d3f1c7055284b969e2de8eaf7d7dc16b51fba94f3325d92d053e12a8/django-rest-auth-0.2.tar.gz#sha256=04ae1a5d991692293ec95a10b517bdb26b41823a645400dc0b899d9f538013b9 (from https://pypi.org/simple/django-rest-auth/), version: 0.2
Found link https://files.pythonhosted.org/packages/46/87/816fcc68a4552916cb82eef40dfd1bd752f831a329e927b96b7f9c6c0db7/django-rest-auth-0.2.1.tar.gz#sha256=3306e739bb8f34d47285c9e1616f75a9d8b4f6985102d68509d5aec5af62c760 (from https://pypi.org/simple/django-rest-auth/), version: 0.2.1
... about 20 more of these
Good luck. Sorry I couldn't give you an exact solution.