Installation fails on Mac OS 12

[lordfeck]

Greetings,

I run Mac OS 12.3 Monterey.

I went to install pelican-thumbnailer using the system supplied Python distribution and it failed with the following error whilst building Pillow:

      [............]
      copying src/PIL/PpmImagePlugin.py -> build/lib.macosx-12-x86_64-3.9/PIL
      copying src/PIL/FtexImagePlugin.py -> build/lib.macosx-12-x86_64-3.9/PIL
      running egg_info
      writing src/Pillow.egg-info/PKG-INFO
      writing dependency_links to src/Pillow.egg-info/dependency_links.txt
      writing top-level names to src/Pillow.egg-info/top_level.txt
      reading manifest file 'src/Pillow.egg-info/SOURCES.txt'
      reading manifest template 'MANIFEST.in'
      warning: no files found matching '*.c'
      warning: no files found matching '*.h'
      warning: no files found matching '*.sh'
      warning: no previously-included files found matching '.appveyor.yml'
      warning: no previously-included files found matching '.coveragerc'
      warning: no previously-included files found matching '.editorconfig'
      warning: no previously-included files found matching '.readthedocs.yml'
      warning: no previously-included files found matching 'codecov.yml'
      warning: no previously-included files matching '.git*' found anywhere in distribution
      warning: no previously-included files matching '*.pyc' found anywhere in distribution
      warning: no previously-included files matching '*.so' found anywhere in distribution
      no previously-included directories found matching '.ci'
      adding license file 'LICENSE'
      writing manifest file 'src/Pillow.egg-info/SOURCES.txt'
      running build_ext
      
      
      The headers or library files could not be found for zlib,
      a required dependency when compiling Pillow from source.
      
      Please see the install instructions at:
         https://pillow.readthedocs.io/en/latest/installation.html
      
      Traceback (most recent call last):
        File "/private/tmp/pip-install-s19uuh84/pillow_ddc2d36086314b8da9da4e973b335324/setup.py", line 864, in <module>
          setup(
        File "/usr/local/lib/python3.9/site-packages/setuptools/__init__.py", line 155, in setup
          return distutils.core.setup(**attrs)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 148, in setup
          return run_commands(dist)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 163, in run_commands
          dist.run_commands()
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 967, in run_commands
          self.run_command(cmd)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 986, in run_command
          cmd_obj.run()
        File "/usr/local/lib/python3.9/site-packages/setuptools/command/install.py", line 68, in run
          return orig.install.run(self)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/command/install.py", line 670, in run
          self.run_command('build')
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/cmd.py", line 313, in run_command
          self.distribution.run_command(command)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 986, in run_command
          cmd_obj.run()
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/command/build.py", line 135, in run
          self.run_command(cmd_name)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/cmd.py", line 313, in run_command
          self.distribution.run_command(command)
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 986, in run_command
          cmd_obj.run()
        File "/usr/local/lib/python3.9/site-packages/setuptools/_distutils/command/build_ext.py", line 339, in run
          self.build_extensions()
        File "/private/tmp/pip-install-s19uuh84/pillow_ddc2d36086314b8da9da4e973b335324/setup.py", line 694, in build_extensions
          raise RequiredDependencyException(f)
      __main__.RequiredDependencyException: zlib
      
      During handling of the above exception, another exception occurred:
      
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/private/tmp/pip-install-s19uuh84/pillow_ddc2d36086314b8da9da4e973b335324/setup.py", line 918, in <module>
          raise RequiredDependencyException(msg)
      __main__.RequiredDependencyException:
      
      The headers or library files could not be found for zlib,
      a required dependency when compiling Pillow from source.
      
      Please see the install instructions at:
         https://pillow.readthedocs.io/en/latest/installation.html
      
      
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.

I tried installing Pillow manually using pip3, but it installed a newer version (9.1.x) than that requested by Pelican-Thumbnailer. I also used brew to install zlib, as the makefile requested, but alas the problem persisted. It may be due to header/includes missing where to find the zlib source.

I'd appreciate any help/advice, or indeed if this could be patched in a future release.

Thanks very much.

[lordfeck]

Update, I found a temporary workaround thanks to this.

First, install zlib using Homebrew.

Then run this in your shell:

export CPPFLAGS="-I$(brew --prefix zlib)/include"

Then run pip3 install pelican-thumbnailer. Pillow 7.2.0 builds successfully and thumbnailer may be installed.

[justinmayer]

Hi @lordfeck. I wouldn't recommend using the Python interpreter included with MacOS Command-Line Tools. It can cause myriad issues, including the one you experienced, and for the most part I think it is best that folks pretend that it does not exist.

I wrote an article that documents the method I recommend, which uses asdf and its Python plugin to install Python.

[lordfeck]

@justinmayer thanks kindly for your response. I've actually had problems in the past with the bundled Python, I thought they were one-offs, but I think there is a pattern here! I'll have a go at the method you've detailed using asdf.

I'd like to add that I greately appreciate your work on Pelican - I was looking for a capable, non-bloated but extensible SSG and it suits that use case perfectly.

Offtopic, but I'd like to share that I made my own custom theme in Jinja then used it to build a blog/personal website at www.thran.uk. Your project's documentation was a great aid in this task, especially in how it described the objects, so I have the site reliably working with my slightly strange pagination rules. When I have a spare moment, I would be willing adapt the theme to be more generic and contribute it to the project, if you think it is suitable.