pyenv BUILD FAILED while trying (pyenv install -v 3.9.0) on wsl2 ubuntu 20.04

Question

SOLVED: the solution was I needed zlib1g-dev

This is the error pyenv produces

Traceback (most recent call last):
  File "<frozen zipimport>", line 520, in _get_decompress_func
ModuleNotFoundError: No module named 'zlib'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<frozen zipimport>", line 568, in _get_data
  File "<frozen zipimport>", line 523, in _get_decompress_func
zipimport.ZipImportError: can't decompress data; zlib not available

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 6, in <module>
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/runpy.py", line 206, in run_module
    mod_name, mod_spec, code = _get_module_details(mod_name)
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/runpy.py", line 147, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/runpy.py", line 111, in _get_module_details
    __import__(pkg_name)
  File "<frozen zipimport>", line 241, in load_module
  File "<frozen zipimport>", line 709, in _get_module_code
  File "<frozen zipimport>", line 570, in _get_data
zipimport.ZipImportError: can't decompress data; zlib not available
Traceback (most recent call last):
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/ensurepip/__main__.py", line 5, in <module>
    sys.exit(ensurepip._main())
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/ensurepip/__init__.py", line 210, in _main
    return _bootstrap(
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/ensurepip/__init__.py", line 129, in _bootstrap
    return _run_pip(args + [p[0] for p in _PROJECTS], additional_paths)
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/ensurepip/__init__.py", line 38, in _run_pip
    return subprocess.run([sys.executable, "-c", code], check=True).returncode
  File "/tmp/python-build.20201212114143.1082/Python-3.9.0/Lib/subprocess.py", line 524, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['/tmp/python-build.20201212114143.1082/Python-3.9.0/python', '-c', '\nimport runpy\nimport sys\nsys.path = [\'/tmp/tmpk898xfhs/setuptools-49.2.1-py3-none-any.whl\', \'/tmp/tmpk898xfhs/pip-20.2.3-py2.py3-none-any.whl\'] + sys.path\nsys.argv[1:] = [\'install\', \'--no-cache-dir\', \'--no-index\', \'--find-links\', \'/tmp/tmpk898xfhs\', \'--root\', \'/\', \'--upgrade\', \'setuptools\', \'pip\']\nrunpy.run_module("pip", run_name="__main__", alter_sys=True)\n']' returned non-zero exit status 1.
make: *** [Makefile:1254: install] Error 1

I have found nothing on this when googling and have no idea what is going on. the steps that I have done are, first installing the pyenv installer and running that script then trying to run (pyenv install -v 3.9.0)

the system does have python3.8 installed and pyenv does seem to know about it but it still will not let me install 3.9.0

EDIT: I should also throw in that in order to let pyenv know about the system version of python I did this (sudo ln -s /usr/bin/python3 /usr/bin/python). Another thing is I also tried installing 3.9.0 with a tool called asdf and that resulted in the same error

EDIT2: It seems like im missing zlib from the traceback but Im on ubuntu and do have zlib1g installed and from what I looked up thats what zlib is on ubuntu 20.04 im going to try and find more info on the zlib and see if I need to install something else

Answer 1

I had a similar problem trying to install Python 3.8 with asdf (which uses the same backend as pyenv) on WSL2/Ubutnu18, and installing zlib1g-dev was not enough to solve it as stated by the question's author.

Therefore, as a more general solution, I have found that installing all dependencies recommended by pyenv for Ubuntu did solve the problem for asdf (and I suspect for pyenv as well). The dependencies for different OS can be found here:https://github.com/pyenv/pyenv/wiki#suggested-build-environment

I hope this is useful for others!

PS: This resource might be useful as well for similar issues: https://github.com/pyenv/pyenv/wiki/Common-build-problems