package installed but not in requirements.txt about heroku-buildpack-python

[kennethreitz]

This is a limitation of the current tooling.

Ideally, we'd have cached downloads and install every dependency on every push. Unfortunately, modules with c extensions make this a bit impractical.

Luckily, I'm working on some tool that will fix this.

[aljosa]

any hack/tip which would allow me now to remove package piston?

if i don't remove it my app will never start and the only way i can think is to remove heroku app and create it again (not an option for this app).

maybe some way to reset virtualenv?

[kennethreitz]

The best thing to do at this time is flush the cache. You can ask support to do this for you.

[aljosa]

still waiting for support to reset virtualenv so i'm trying to find a way to fix this.
any way i can use a modified buildpack on an existing app?
any tips appreciated

[kennethreitz]

You can actually use the purge branch of this repo to do that :)

[aljosa]

thanks for suggestion but the part i didn't understand is if i can apply a different buildpack next time i push changes w/o delete/create heroku app?

[kennethreitz]

@aljosa yes, you can do the following:

$ heroku config:add BUILDPACK_URL=git://github.com/heroku/heroku-buildpack-python.git

[ppp23]

this is still an issue for me and others it seems: http://stackoverflow.com/questions/14368027/how-can-i-flush-the-heroku-buildpack-cache-dir
i had to re-install the piston package from source for some unreleased fixes, but the old package still remains inside the site-packages.

[kennethreitz]

Specify a different runtime, and your cache will be purged.

https://devcenter.heroku.com/articles/python-runtimes#changing-runtimes

[ppp23]

ok, thank you, even if it would be nice to have an easier/quicker method, this works for me

[kennethreitz]

Indeed, it will be automatic one day, but some tools need to be written first ;)

[victorfontes]

@kennethreitz Just saved mine and my customers life.

Looking foward for an easier way to do that on heroku.

[mightyiam]

+1

[apragacz]

+1

[eroninjapan]

@kennethreitz Is modifying runtime.txt, deploying, reverting runtime.txt still the best method to accomplish purging the cached dependencies myself? I tried using the Heroku Repo plugin (https://github.com/heroku/heroku-repo) purge_cache command but it's not working as expected.

[kennethreitz]

Packages are now automatically uninstalled when removed from requirements.txt

[wooyek]

I have no versions in the requirements.txt. How can I make sure that the latest packages will be installed on deploy to heroku?

PS. No versions freeze is on purpose. I know it's not the best practice. but I want my CI to catch any incompatibilities as quicly as it can and I don't want to keep to versions of requirements file.

[wooyek]

For anyone who stumbles here, as a workaround you can use post_compile hook, eg.:

#!/usr/bin/env bash
# File path should be ./bin/post_compile
# https://gist.github.com/kylefox/7044491259b6b2586ca1

echo "UPGRADE_REQUIREMENTS: $UPGRADE_REQUIREMENTS"

if [[ "$UPGRADE_REQUIREMENTS" == "True" ]]; then
    echo "====> Upgrading requirements"
    pip install -r requirements.txt -U
fi
echo "====> Installed versions"
pip freeze

…or similar.