PyEnv BUILD FAILED installing Python on MacOS

Question

While trying to install Python 3.6.6 (for Airflow) using PyEnv on MacOS, I am encountering build failure with following stack-trace

File "/private/var/folders/6y/kf699bqj2sgcgjshb20fr5zh0000gn/T/python-build.20180721180716.86347/Python-3.6.6/Lib/xmlrpc/client.py", line 138, in <module>     from xml.parsers import expat   File "/private/var/folders/6y/kf699bqj2sgcgjshb20fr5zh0000gn/T/python-build.20180721180716.86347/Python-3.6.6/Lib/xml/parsers/expat.py", line 4, in <module>     from pyexpat import * ModuleNotFoundError: No module named 'pyexpat' make: *** [install] Error 1  BUILD FAILED (OS X 10.13.6 using python-build 20180424)  Inspect or clean up the working tree at /var/folders/6y/kf699bqj2sgcgjshb20fr5zh0000gn/T/python-build.20180721180716.86347 Results logged to /var/folders/6y/kf699bqj2sgcgjsh 

I've followed the steps mentioned in the docs for setting-up PyEnv on Mac via Homebrew.

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Environment / Framework versions

• MacOS High Sierra 10.13.6
• Homebrew 1.7.1
• PyEnv 1.2.6
• Existing Python distributions
  • Python 2.7.15 [GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
  • Python 3.7.0 [Clang 9.0.0 (clang-900.0.39.2)] on darwin

Answer 1

I had this problem with Mojave and Python 3.7.3.

This worked for me:

SDKROOT=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk MACOSX_DEPLOYMENT_TARGET=10.14 pyenv install 3.7.3 

Answer 2

The only way I could get it working is through the below prefixes before installing

CFLAGS="-I$(brew --prefix readline)/include -I$(brew --prefix openssl)/include  -I$(xcrun --show-sdk-path)/usr/include" \ LDFLAGS="-L$(brew --prefix readline)/lib -L$(brew --prefix openssl)/lib" \ PYTHON_CONFIGURE_OPTS=--enable-unicode=ucs2 \ pyenv install -v 3.7.1