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I was upgrading from 13.10 to 14.04 (dev for now, stable in a few hours) using do-release-upgrade and encountered the following problem:

Can not upgrade 

Your python install is corrupted. Please fix the '/usr/bin/python' symlink.

I solved the problem after messing around a bit, so I'd like to share my solution here. Hope this could help someone.

wjandrea
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4ae1e1
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5 Answers5

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My problem turned out to be solely due to an altered /usr/bin/python symlink as suggested in the error message. I was using update-alternatives with /usr/bin/python so it was pointing to /etc/alternatives/python. Turned out that do-release-upgrade is really strict with this symlink and merely selecting python2.7 with update-alternatives isn't enough, so I ended up forcing it to its original state:

sudo ln -sf /usr/bin/python2.7 /usr/bin/python

And that solved the problem.

If this doesn't work for you, then I guess you have a genuinely corrupted python install. I'd suggest

sudo apt-get install --reinstall python
4ae1e1
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  • @BenjaminKohl Glad it helped :) – 4ae1e1 Apr 24 '14 at 07:19
  • Wasn't `/etc/alternatives/python` symlinked to `/usr/bin/python2.7`? did something else has higher priority? – heemayl Jun 19 '15 at 16:34
  • I am afraid you are getting it backwards....`/usr/bin/python2.7` is the actual binary, it should never be the symlink, the symlink is the `/etc/alternatives/python`..do you mind checking it again? – heemayl Jun 19 '15 at 17:31
  • @heemayl Sorry, misread your comment + typo on my part. `/usr/bin/python` is a symlink to `/etc/alternatives/python` (of course `/usr/bin/python2.7` is the binary, but that's not the problem here). – 4ae1e1 Jun 19 '15 at 17:33
  • And yes, `/etc/alternatives/python` is then symlinked to whatever you selected (not necessarily `/usr/bin/python2.7` — why would you even need `update-alternatives` in that case?), but the point is symlinking is not allowed for `/usr/bin/python` when you `do-release-upgrade`. – 4ae1e1 Jun 19 '15 at 17:34
  • In my case this was not enough: I also had to tweak /usr/share/python/debian_defaults so that it matches the version /usr/bin/python points to. – Pietro Braione Jun 15 '17 at 08:58
  • In my case I wasn't using alternatives ("update-alternatives --get-selections" didn't show python). Python was also working happily with apparently good links for /usr/bin/python and python2. Simply remaking the link for /usr/bin/python was enough to allow the update to work. FWIW. My Ubuntu is on a VMware VM. – John Jefferies Jun 11 '18 at 10:32
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this one is correct:

sudo update-alternatives --remove-all python
sudo ln -sf /usr/bin/python2.7 /usr/bin/python
Vitaliy Kulikov
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    This is absolutely correct. It would not work for me until I also first removed all existing using the `update-alternatives --remove-all python` – TryTryAgain Oct 10 '16 at 17:04
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In Ubuntu 18.10 there is still the same issue.

The /usr/bin/python is linked to an older version. Even later than 2.7 are available but this super-smart process is asking (in 18.10!) for P 2.7. So I gave it and it was accepted.

This solved it for me:

1) delete /usr/bin/python doing sudo rm /usr/bin/python

2) Create a new link sudo ln -sf /usr/bin/python2.7 /usr/bin/python

In 18.10 I could NOT use sudo update-alternatives --remove-all python or sudo apt-get install --reinstall python .

Works for me. Hope it helps you, too.

opinion_no9
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    `ls -sf` overrides the target so 1) is pointless, and 2) is exactly what my answer told you to do. What a waste... – 4ae1e1 Sep 01 '18 at 12:28
  • Dont rant: Your quote is wrong and I told the opposite of what you tell about "... --reinstall python". Yes, my experience with 18.10 is different than yours and I explain this. No need at all for brazen comments. – opinion_no9 Sep 02 '18 at 21:21
  • Saw "If this doesn't work for you, then I guess you have a genuinely corrupted python install."? – 4ae1e1 Sep 02 '18 at 23:31
  • Basically, the lesson is: you read the surroundings and learn why, not just cherrypick whatever code blocks there are, paste them into your terminal (dangerous), and see what sticks. By the way, your `sudo rm` is still pointless. – 4ae1e1 Sep 02 '18 at 23:34
  • Your comments are welcome. – opinion_no9 Sep 04 '18 at 09:21
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    True, it works on 18.10. Thanks. – Wings Sep 18 '18 at 13:01
  • Step 2 fixes the issue. Very bizarre given the default is Python3 now! – DaveStephens Apr 19 '19 at 16:11
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If you run into this regarding /usr/bin/python3 then:

sudo update-alternatives --remove-all python3
sudo ln -sf /usr/bin/python3.6 /usr/bin/python3

Make sure to symlink python3.6 and not 3.7. At least that was required when upgrading Ubuntu 18.10 to 19.04.

Jana
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For Ubuntu 19.04 the default python version is 3.7 . I got same error while upgrading to Ubuntu 19.10, and, the following helped:

sudo apt-get install --reinstall python3
sudo ln -sf /usr/bin/python3.7 /usr/bin/python3

In case you have very serious problems with your python package, the only way left is to force remove it, and then reinstall it:

sudo dpkg --remove --force-remove-reinstreq --force-depends python3
sudo apt-get -f install
Vibhu Vaibhav
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