RHEL/Pyenv: No module named '_tkinter'

Question

I'm trying to use Matplotlib on RHEL using a pyenv installed version of python 3.6.5. (installed using the following command)

→ pyenv install 3.6.5

Installing Python-3.6.5...
python-build: use readline from homebrew
Installed Python-3.6.5 to /home/swp1g17/.pyenv/versions/3.6.5
→ pyenv global 3.6.5

I'm presented with the following error, and have found many questions that have a similar issue:

Python 3.6.5 (default, Apr  5 2018, 17:22:36) 
[GCC 5.5.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tkinter
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/swp1g17/.pyenv/versions/3.6.5/lib/python3.6/tkinter/__init__.py", line 36, in <module>
    import _tkinter # If this fails your Python may not be configured for Tk
ModuleNotFoundError: No module named '_tkinter'

However the suggested solution is usually to install tkinter using a package manager. However I've tried installing:

   2872  sudo yum install rh-python36-python-tkinter
   2873  sudo yum install rh-python35-python-tkinter                                                                                               
   2874  sudo yum install rh-python34-python-tkinter                                                                                               
   2891  sudo yum install tkinter                                                                                                                  
   2893  sudo yum install python36-tkinter                                                                                                         
   2902  sudo yum install gcc zlib-devel bzip2 bzip2-devel readline-devel sqlite sqlite-devel openssl-devel tk-devel gdbm-devel ncurses-devel gl.. 
   2916  sudo yum install tkinter.x86_64 rh-python36-python-tkinter.x86_64 rh-python35-python-tkinter.x86_64 rh-python34-python-tkinter.x86_64 p.. 
   2921  sudo yum install tcl                                                                                                                      
   2933  sudo yum install tk-devel                                                                                                                 
   2934  sudo yum install tk                                                                                                                       
   3000  sudo yum install tkinter                                                                                                                  
   3026  sudo yum install tix                                                                                                                      
   3031  sudo yum install tk                                                                                                                       
   3032  sudo yum install tk-devel                                                                                                                 
>  3033  sudo yum install tcl-devel

with each already having been installed or making no difference (having rebuilt python each time a new package was installed.

The system python is able to locate tkinter:

→ /usr/bin/python3.6
Python 3.6.3 (default, Jan  4 2018, 16:40:53) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tkinter
>>> 

so I'm unsure how to install python using pyenv and have it use the same version of tkinter?

---

UPDATE: Having found that build configuration options can be set using $PYTHON_CONFIGURE_OPTS I've tried specifying the library locations using (for linuxbrew downloaded tcl/tk):

export PYTHON_CONFIGURE_OPTS="--with-tcltk-includes=-I/home/linuxbrew/.linuxbrew/opt/tcl-tk/include --with-tcltk-libs=-L/home/linuxbrew/.linuxbrew/opt/tcl-tk/lib"
pyenv install 3.6.5

and (using system tcl/tk):

export PYTHON_CONFIGURE_OPTS="--with-tcltk-includes=-I/usr/include --with-tcltk-libs=-L/usr/lib64"
pyenv install 3.6.5

each with no luck. System tcl/tk was found using:

→ whereis tcl        
tcl: /usr/lib64/tcl8.5 /usr/include/tcl.h /usr/share/tcl8.5
→ whereis tcl        
tcl: /usr/lib64/tcl8.5 /usr/include/tcl.h /usr/share/tcl8.5

Answer 1

Below is my step-by-step howto using pyenv 1.2.11 on Ubuntu 19.04 and Fedora 29:

1. Install pyenv

   • Using the installer

     git clone https://github.com/pyenv/pyenv-installer
     chmod +x pyenv-installer/bin/pyenv-installer
     pyenv-installer/bin/pyenv-installer
     

   • By hand

     git clone https://github.com/pyenv/pyenv.git ~/.pyenv
     

2. Setup pyenv

   $ cat >> ~/.bashrc
   # Load pyenv automatically
   export PATH="~/.pyenv/bin:$PATH"
   eval "$(pyenv init -)"
   

   ^{Ctrl + D}

   $ source ~/.bashrc
   
   $ pyenv --version
   pyenv 1.2.11-8-g070e1c85
   

3. Install dependencies

   • Ubuntu 19.04 Disco Dingo

     sudo apt install tk-dev         # <-- This has fixed my issue
     sudo apt install libbz2-dev
     sudo apt install libreadline-dev
     sudo apt install libsqlite3-dev
     

   • Fedora 29

     sudo dnf install tk-devel       # <-- This may fix your issue
     sudo dnf install libbz2-dev
     sudo dnf install readline-devel
     sudo dnf install libsqlite3x-devel
     sudo dnf install openssl-devel
     sudo dnf install make
     

4. Install Python-3.6.8 using pyenv

   pyenv install 3.6.8
   

5. Check installation

   $ pyenv local 3.6.8  # Create file .python-version
   $ python --version
   Python 3.6.8
   

6. Install modules

   python -m pip install --user --upgrade pip
   python -m pip install --user pipenv
   ...
   

7. Example of pipenv usage

   cd /path/where/your/Pipfile/is/located/
   pyenv local 3.6.8
   python -m pipenv --rm  # first time: No virtualenv has been created...
   python -m pipenv update --dev
   python -m pipenv run python -m nose   # my unit tests