Hi Team
I was trying to build a project in vercel and realised vercel is using python 3.9.8 instead of 3.12 which is leading to multiple build fails. Is there a way to fix the python version of the runtime?
This is the pipfile I’m using, but the version is still 3.9.8
Hi @krypticmouse, welcome to the Vercel Community!
Sorry that you’re facing this issue. Can you confirm you are following this:
When upgrading to
3.12, ensure you set Node.js20.xor22.xin your project settings.
Hi Anshuman!
I did do that but I’m not sure why but when I do that pip works but all the dependencies it installs don’t work, almost as if the shell is different
Installing collected packages: webencodings, wcwidth, pytz, pure-eval, ptyprocess, paginate, magicattr, fastjsonschema, zipp, xxhash, watchdog, urllib3, ujson, tzdata, typing_extensions, traitlets, tqdm, tornado, tinycss2, tenacity, soupsieve, sniffio, six, rpds-py, regex, pyzmq, pyyaml, python-dotenv, pygments, pycparser, pyarrow, psutil, propcache, prompt_toolkit, platformdirs, pillow, pexpect, pathspec, parso, pandocfilters, packaging, numpy, nest-asyncio, multidict, mkdocs-material-extensions, mistune, mergedeep, mdurl, markupsafe, markdown, jupyterlab-pygments, json-repair, joblib, jiter, idna, h11, greenlet, fsspec, frozenlist, filelock, executing, distro, diskcache, dill, defusedxml, decorator, debugpy, colorlog, colorama, cloudpickle, click, charset-normalizer, certifi, cachetools, bleach, backrefs, backoff, babel, attrs, asttokens, annotated-types, aiohappyeyeballs, yarl, stack_data, sqlalchemy, requests, referencing, pyyaml-env-tag, python-dateutil, pymdown-extensions, pydantic-core, multiprocess, mkdocs-get-deps, matplotlib-inline, markdown-it-py, Mako, jupyter-core, jinja2, jedi, ipython-pygments-lexers, importlib-metadata, httpcore, griffe, cssselect2, comm, cffi, beautifulsoup4, anyio, aiosignal, tiktoken, rich, pydantic, pandas, mdit-py-plugins, jupyter-client, jsonschema-specifications, ipython, huggingface-hub, httpx, ghp-import, cairocffi, asyncer, alembic, aiohttp, tokenizers, optuna, openai, mkdocs, jsonschema, ipykernel, cairosvg, nbformat, mkdocs-redirects, mkdocs-material, mkdocs-autorefs, litellm, datasets, nbclient, mkdocstrings, jupytext, dspy, nbconvert, mkdocstrings-python, mkdocs-jupyter
Successfully installed Mako-1.3.9 aiohappyeyeballs-2.6.1 aiohttp-3.11.14 aiosignal-1.3.2 alembic-1.15.1 annotated-types-0.7.0 anyio-4.9.0 asttokens-3.0.0 asyncer-0.0.8 attrs-25.3.0 babel-2.17.0 backoff-2.2.1 backrefs-5.8 beautifulsoup4-4.13.3 bleach-6.2.0 cachetools-5.5.2 cairocffi-1.7.1 cairosvg-2.7.1 certifi-2025.1.31 cffi-1.17.1 charset-normalizer-3.4.1 click-8.1.8 cloudpickle-3.1.1 colorama-0.4.6 colorlog-6.9.0 comm-0.2.2 cssselect2-0.8.0 datasets-3.4.1 debugpy-1.8.13 decorator-5.2.1 defusedxml-0.7.1 dill-0.3.8 diskcache-5.6.3 distro-1.9.0 dspy-2.6.14 executing-2.2.0 fastjsonschema-2.21.1 filelock-3.18.0 frozenlist-1.5.0 fsspec-2024.12.0 ghp-import-2.1.0 greenlet-3.1.1 griffe-1.6.2 h11-0.14.0 httpcore-1.0.7 httpx-0.28.1 huggingface-hub-0.29.3 idna-3.10 importlib-metadata-8.6.1 ipykernel-6.29.5 ipython-9.0.2 ipython-pygments-lexers-1.1.1 jedi-0.19.2 jinja2-3.1.6 jiter-0.9.0 joblib-1.4.2 json-repair-0.40.0 jsonschema-4.23.0 jsonschema-specifications-2024.10.1 jupyter-client-8.6.3 jupyter-core-5.7.2 jupyterlab-pygments-0.3.0 jupytext-1.16.7 litellm-1.63.7 magicattr-0.1.6 markdown-3.7 markdown-it-py-3.0.0 markupsafe-3.0.2 matplotlib-inline-0.1.7 mdit-py-plugins-0.4.2 mdurl-0.1.2 mergedeep-1.3.4 mistune-3.0.2 mkdocs-1.6.1 mkdocs-autorefs-1.4.1 mkdocs-get-deps-0.2.0 mkdocs-jupyter-0.25.1 mkdocs-material-9.6.9 mkdocs-material-extensions-1.3.1 mkdocs-redirects-1.2.2 mkdocstrings-0.29.0 mkdocstrings-python-1.16.7 multidict-6.2.0 multiprocess-0.70.16 nbclient-0.10.2 nbconvert-7.16.6 nbformat-5.10.4 nest-asyncio-1.6.0 numpy-2.2.4 openai-1.61.0 optuna-4.2.1 packaging-24.2 paginate-0.5.7 pandas-2.2.3 pandocfilters-1.5.1 parso-0.8.4 pathspec-0.12.1 pexpect-4.9.0 pillow-10.4.0 platformdirs-4.3.7 prompt_toolkit-3.0.50 propcache-0.3.0 psutil-7.0.0 ptyprocess-0.7.0 pure-eval-0.2.3 pyarrow-19.0.1 pycparser-2.22 pydantic-2.10.6 pydantic-core-2.27.2 pygments-2.19.1 pymdown-extensions-10.14.3 python-dateutil-2.9.0.post0 python-dotenv-1.0.1 pytz-2025.1 pyyaml-6.0.2 pyyaml-env-tag-0.1 pyzmq-26.3.0 referencing-0.36.2 regex-2024.11.6 requests-2.32.3 rich-13.9.4 rpds-py-0.23.1 six-1.17.0 sniffio-1.3.1 soupsieve-2.6 sqlalchemy-2.0.39 stack_data-0.6.3 tenacity-9.0.0 tiktoken-0.9.0 tinycss2-1.4.0 tokenizers-0.21.1 tornado-6.4.2 tqdm-4.67.1 traitlets-5.14.3 typing_extensions-4.12.2 tzdata-2025.2 ujson-5.10.0 urllib3-1.26.6 watchdog-6.0.0 wcwidth-0.2.13 webencodings-0.5.1 xxhash-3.5.0 yarl-1.18.3 zipp-3.21.0
WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
[notice] A new release of pip is available: 24.0 -> 25.0.1
[notice] To update, run: python3.12 -m pip install --upgrade pip
sh: line 1: mkdocs: command not found
Error: Command "mkdocs build" exited with 127
like in this case mkdocs is installed but it’s not able to identify it in build
Hi @krypticmouse, you shouldn’t do pip install manually in Vercel.
Hi @anshumanb!
Thank you so much for the response!!
What should be the proper way out for this?
I have a pipfile but what should be my install command?
Hi @krypticmouse, Vercel will install the packages automatically from the requirements file.
Try removing the requirements file and see if that helps.
Hello, I have a project running MkDocs on Vercel,
but I recently discovered that there is a problem with it working on Node 20.x and 22.x.
I’ve commented on the MkDocs discussion about the solution to this, and I’ve also updated Vercel-MkDocs.
I hope this will lead to your solution.
p.s. I’ve been a Vercel user since the now.sh days. This is my first post in this community.
To the Vercel staff,
Unfortunately, the way Python works in Vercel is different between Node 18.x and Node 20.x, 22.x.
As a result, we may see an increase in reports of Python-related issues over the next few months.
Specifically, the installed Python library (pip) is not visible and is marked as Not Found.
MkDocs has experienced this. I needed to make some modifications to the source.
Hopefully this can be resolved at the build image level before Node18 expires.
Hi @balloon, thanks for highlighting this. Glad to meet another now.sh user I’ve been a Vercel user since then. 
We’ve shared this information with out team. I’ll keep the thread updated.
Hey, sorry for the late reply
This does turn out to be expected. Python has upgraded from 3.9 to 3.12 and the available binaries are python3 and pip3