pip uses incorrect cached package version, instead of the user-specified version

Question

I need to install psycopg2 v2.4.1 specifically. I accidentally did:

pip install psycopg2

Instead of:

pip install psycopg2==2.4.1

That installs 2.4.4 instead of the earlier version.

Now even after I pip uninstall psycopg2 and attempt to reinstall with the correct version, it appears that pip is re-using the cache it downloaded the first time.

How can I force pip to clear out its download cache and use the specific version I'm including in the command?

Diocletian

Answer 1

If using pip 6.0 or newer, try adding the --no-cache-dir option (source).

If using pip older than pip 6.0, upgrade it with pip install -U pip.

Drooff

I looked in ~/.pip but its an empty directory. Your tip on --ignore-installed did the trick! – Diocletian

On OSX, I had to delete the pip related directories in $TMPDIR – Penitentiary

If using virtualenv you might have to delete envs/{yourenvsname}/build/{packageinquestion} dir... – Compete

In windows: I've seen pip caching directory is in ~\AppData\Local\pip\cache – Morbidity

@Dr Manhattan's answer locates the pip cache on the major OSs. – Jeffersonjeffery

You have to do python -m pip install -U pip on Windows. (It can't upgrade due to locking the pip.exe file otherwise.) – Doge

This answer is only partially correct. --no-cache-dir does not delete contents of cache folder. – Jellaba

This answer was correct back in 2012 - the answer from @pradyunsg is much better practice now. – Ethyl

Answer 2

Clear the cache directory where appropriate for your system

Linux and Unix

~/.cache/pip  # and it respects the XDG_CACHE_HOME directory.

OS X

~/Library/Caches/pip

Windows

%LocalAppData%\pip\Cache

UPDATE

With pip 20.1 or later, you can find the full path for your operating system easily by typing this in the command line:

pip cache dir

Example output on my Ubuntu installation:

➜ pip3 cache dir
/home/tawanda/.cache/pip

Mainz

The current most-up-to-date answer (posted by a pip maintainer) is https://mcmap.net/q/49603/-pip-uses-incorrect-cached-package-version-instead-of-the-user-specified-version. The best approach now is pip cache purge. – Ritzy

pip cache purge only works on pip 20.1 according to the answer you link to. This answer seems to apply to all pip versions and all platforms, which would make it more generally useful but I don't know if that's the case. – Dietetic

Answer 3

With pip 20.1 or later, you can do:

• pip cache remove matplotlib: removes all wheel files related to matplotlib from pip's cache.
• pip cache purge: to clear all wheel files from pip's cache.
• pip cache dir: to get the location of the cache.

If you want to not use the pip cache for some reason (which is a bad idea, according the official docs), your options are:

• pip install --no-cache-dir <package>: install a package without using the cache, for just this run.
• pip config set global.no-cache-dir false: configure pip to not use the cache "globally" (in all commands).

---

Some history around this question (puts on pip maintainer hat):

The specific issue of "installing the wrong version due to caching" issue mentioned in the question was fixed in pip 1.4, back in 2013!)

Fix a number of issues related to cleaning up and not reusing build directories. (#413, #709, #634, #602, #939, #865, #948)

Since pip 6.0 (back in 2014!), pip install, pip download and pip wheel commands can be told to avoid using the cache with the --no-cache-dir option. (e.g. pip install --no-cache-dir <package>)

Back then, yes, passing --no-cache-dir was the only option to avoid this bug. So... it's a bit unfortunate that this is the top search result on "pip cache remove". :)

Since pip 10.0 (back in 2018!), a pip config command was added, which can be used to configure pip to always ignore the cache. This was always possible by manually editing the relevant files, but this surfaced that ability to the command line. Details on pip's configuration mechanisms is available here.

Since pip 20.1, pip has a pip cache command to manage the contents of pip's cache.

Ritzy

I have pip 20.1.1 but when I try pip cache purge I get next error: ERROR: No matching packages but I installed a lot of different packages already – Prodigious

@mikhail_sam try pip cache list if it doesn't show anything than you don't have anything cached. – Mandamandaean

@RobertLugg looks like you are right! pip cache list returns Nothing cached. – Prodigious

For me pip cache purge and pip cache list suggest cache is empty but du -hs ~/.cache/pip shows 242MB. – Carlcarla

There is a typo in pip config set global.cache-dir false. It should be pip config set global.no-cache-dir false. – Horizontal

I get an error ERROR: unknown command "cache" - maybe you meant "check" – Antilles

@Antilles You're on a verson of pip older than 20.1. – Ritzy

Good point, @Darren; I've edited the answer accordingly, and have added a note on how to re-enable the cache. (Hope I got it right; as noted in this answer, using false is counter-intuitive, but it seems to work; as of (at least) v22.0.3, true also works and seemingly has the same effect(!); to re-enable the cache, the setting must be unset (removed)). – Erythrocyte

Answer 4

From documentation at https://pip.pypa.io/en/latest/reference/pip_install.html#caching:

Starting with v6.0, pip provides an on-by-default cache which functions similarly to that of a web browser. While the cache is on by default and is designed do the right thing by default you can disable the cache and always access PyPI by utilizing the --no-cache-dir option.

Scleroderma

This is the right answer...the link also shows where pip stashes the cache on Linux, Windows & OS X. – Fournier

And to add, if you want to remove the "bad" object from your cache, have a look at the page to find the location of the cache file, and "find" the offending package. Linux is ~/.cache/pip, Mac is ~/Library/Caches/pip, etc. Interestingly, psycopg2 was also my problem package, but it was because the existing package was compiled for a different Postgresql library, which no longer existing on my server. – Cristiecristin

Answer 5

pip can install a package ignoring the cache, like this

pip --no-cache-dir install scipy

Maure

@dafeda's answer provides the same information 4 months ago – Modify

Answer 6

Since pip 20.1b1, which was released on 21 April 2020 and "added pip cache command for inspecting/managing pip’s wheel cache", it is possible to issue this command:

pip cache purge

The reference guide is here:
https://pip.pypa.io/en/stable/reference/pip_cache/
The corresponding pull request is here.

Chrysoberyl

What about pip3? Using pip3 i got ERROR: unknown command "cache" - maybe you meant "check" – Perpend

Then possibly you should upgrade your pip (or pip3, which I think should be the same thing since Python 2 was phased out): pip install --upgrade pip or pip3 install --upgrade pip. – Tampere

Even after updating pip I get the error ERROR: unknown command "cache" - maybe you meant "check" – Antilles

Answer 7

On Ubuntu, I had to delete /tmp/pip-build-root.

Tuberculate

Actually /tmp/pip-build-%username_that_running_pip% – Slurry

On Ubuntu 14 it was /tmp/pip_build_root/ (note underscores) – Yesterday

Answer 8

If you like to set the --no-cache-dir option by default, you can put this into pip.conf:

[global]
no-cache-dir = false

Note 1: It's confusing, but to enable the no-cache-dir option you actually have to set it to false. Pretty silly if you ask me... but that's how it is. There is a github issue to fix this.

Note 2: The location of pip.conf depends on your OS. See the documentation for more info.

Lockyer

Are they really debating for 3 years now about the justification to activate an option using False instead of True ? -REALLY- ? – Orff

Answer 9

I just had a similar problem and found that the only way to get pip to upgrade the package was to delete the $PWD/build (%CD%\build on Windows) directory that might have been left over from a previously unfinished install or a previous version of pip (it now deletes the build directories after a successful install).

Braided

Answer 10

On archlinux pip cache is located at ~/.cache/pip, I could solve my issue by removing the http folder inside it.

Floatable

Answer 11

On my mac I had to remove the cache directory ~/Library/Caches/pip/

Interweave

Answer 12

Simply

rm -d -r "$(pip cache dir)"

Amenable

Answer 13

(pyvenv.d) jdoe$ pip --version       # pip version for this answer (or newer).
pip 21.1.1

(pyvenv.d) jdoe$ pip cache --help    # Review all options available to you.

(pyvenv.d) jdoe$ pip cache dir       # Cache-directory for pip(1).
/home/jdoe/.cache/pip

(pyvenv.d) jdoe$ pip cache purge     # Purge cache-directory (by example).
Files removed: 621                   # If cache-directory is already empty, the
                                     # output will be: "ERROR: No matching packages".

Alvarez

Answer 14

On Windows 7, I had to delete %HOMEPATH%/pip.

Tuberculate

Answer 15

If using virtualenv, look for the build directory under your environments root.

Compete

Answer 16

I had to delete %TEMP%\pip-build On Windows 7

Reseat

Thanks+1. I'm also using Windows 7 and found the folder under my %TEMP%\pip folder. The %TEMP% is defined in your environmental variables if anyone is unsure. – Tannate

Answer 17

On Mac OS (Mavericks), I had to delete /tmp/pip-build/

Spireme

Answer 18

A better way to do it is to delete the cache and rebuild it. In this way, if you install it again for other virtualenv, it will use the cache instead of building every time when you install it.

For example, when you install it, it will say it uses cached wheel,

Processing <some_prefix>/Library/Caches/pip/wheels/d0/c4/e4/e49fd07bca8dda00dd6b4bbc606aa05a25aacb00d45747a47a/horovod-0.19.3-cp37-cp37m-macosx_10_9_x86_64.wh

Just delete that one and restart your install.

Algeciras

Answer 19

(...) it appears that pip is re-using the cache (...)

I'm pretty sure that's not what's happening. Pip used to (wrongly) reuse build directory not cache. This was fixed in version 1.4 of pip which was released on 2013-07-23.

Carnet