example fails on osx due to known bug in brewed pip install --target

Reproduce

On a mac:

• get python 3.6: brew install python3
• make it default interpreter: brew unlink python && brew link python3
• git clone https://github.com/UnitedIncome/serverless-python-requirements
• cd serverless-python-requirements/example
• npm install -g serverless
• [… config aws credentials]
• npm install serverless-python-requirements
• SLS_DEBUG=* sls deploy -v

This is the output:

Serverless: Load command run
Serverless: Load command config
Serverless: Load command config:credentials
Serverless: Load command create
Serverless: Load command install
Serverless: Load command package
Serverless: Load command deploy
Serverless: Load command deploy:function
Serverless: Load command deploy:list
Serverless: Load command deploy:list:functions
Serverless: Load command invoke
Serverless: Load command invoke:local
Serverless: Load command info
Serverless: Load command logs
Serverless: Load command login
Serverless: Load command logout
Serverless: Load command metrics
Serverless: Load command print
Serverless: Load command remove
Serverless: Load command rollback
Serverless: Load command rollback:function
Serverless: Load command slstats
Serverless: Load command plugin
Serverless: Load command plugin
Serverless: Load command plugin:install
Serverless: Load command plugin
Serverless: Load command plugin:uninstall
Serverless: Load command plugin
Serverless: Load command plugin:list
Serverless: Load command plugin
Serverless: Load command plugin:search
Serverless: Load command emit
Serverless: Load command config
Serverless: Load command config:credentials
Serverless: Load command rollback
Serverless: Load command rollback:function
Serverless: Load command requirements
Serverless: Load command requirements:clean
Serverless: Load command requirements:install
Serverless: Invoke deploy
Serverless: Invoke package
Serverless: Invoke aws:common:validate
Serverless: Invoke aws:common:cleanupTempDir
Serverless: Installing required Python packages with python3.6...
 
  Error --------------------------------------------------
 
  Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/local/lib/python3.6/site-packages/pip/commands/install.py", line 342, in run
    prefix=options.prefix_path,
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_set.py", line 784, in install
    **kwargs
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_install.py", line 851, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
    isolated=self.isolated,
  File "/usr/local/lib/python3.6/site-packages/pip/wheel.py", line 247, in move_wheel_files
    prefix=prefix,
  File "/usr/local/lib/python3.6/site-packages/pip/locations.py", line 153, in distutils_scheme
    i.finalize_options()
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/install.py", line 248, in finalize_options
    "must supply either home or prefix/exec-prefix -- not both")
distutils.errors.DistutilsOptionError: must supply either home or prefix/exec-prefix -- not both

 
     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.
 
  Stack Trace --------------------------------------------
 
Error: Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/local/lib/python3.6/site-packages/pip/commands/install.py", line 342, in run
    prefix=options.prefix_path,
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_set.py", line 784, in install
    **kwargs
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_install.py", line 851, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/local/lib/python3.6/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
    isolated=self.isolated,
  File "/usr/local/lib/python3.6/site-packages/pip/wheel.py", line 247, in move_wheel_files
    prefix=prefix,
  File "/usr/local/lib/python3.6/site-packages/pip/locations.py", line 153, in distutils_scheme
    i.finalize_options()
  File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework/Versions/3.6/lib/python3.6/distutils/command/install.py", line 248, in finalize_options
    "must supply either home or prefix/exec-prefix -- not both")
distutils.errors.DistutilsOptionError: must supply either home or prefix/exec-prefix -- not both

    at ServerlessPythonRequirements.installRequirements (/Users/me/serverless-python-requirements/example/node_modules/serverless-python-requirements/lib/pip.js:76:11)
From previous event:
    at PluginManager.invoke (/usr/local/lib/node_modules/serverless/lib/classes/PluginManager.js:366:22)
    at PluginManager.spawn (/usr/local/lib/node_modules/serverless/lib/classes/PluginManager.js:384:17)
    at Deploy.BbPromise.bind.then.then (/usr/local/lib/node_modules/serverless/lib/plugins/deploy/deploy.js:120:50)
From previous event:
    at Object.before:deploy:deploy [as hook] (/usr/local/lib/node_modules/serverless/lib/plugins/deploy/deploy.js:110:10)
    at BbPromise.reduce (/usr/local/lib/node_modules/serverless/lib/classes/PluginManager.js:366:55)
From previous event:
    at PluginManager.invoke (/usr/local/lib/node_modules/serverless/lib/classes/PluginManager.js:366:22)
    at PluginManager.run (/usr/local/lib/node_modules/serverless/lib/classes/PluginManager.js:397:17)
    at variables.populateService.then (/usr/local/lib/node_modules/serverless/lib/Serverless.js:104:33)
    at runCallback (timers.js:789:20)
    at tryOnImmediate (timers.js:751:5)
    at processImmediate [as _immediateCallback] (timers.js:722:5)
From previous event:
    at Serverless.run (/usr/local/lib/node_modules/serverless/lib/Serverless.js:91:74)
    at serverless.init.then (/usr/local/lib/node_modules/serverless/bin/serverless:42:50)
    at <anonymous>
 
  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Forums:        forum.serverless.com
     Chat:          gitter.im/serverless/serverless
 
  Your Environment Information -----------------------------
     OS:                     darwin
     Node Version:           8.9.3
     Serverless Version:     1.24.1

Resolutions

• Avoiding --target flag would be best. If not possible:
• Add setup.cfg to example root with this content:

[install]
prefix=

• Use the dockerImage: lambci/lambda:build-python3.6 directive in example?

[heri16]

Just a note, using the setup.cfg workaround causes some python wheels to not work, meaning pip will recompile wheels from source tar. Thus whole recompilation process is expensive and might take a long time to complete.

[avishayp]

The setup.cfg “fix” works, but it’s an ugly workaround that should be avoided. Once the deployment I’m working on works I’ll submit PR with it as an example and call it mac_example.