Buildozer Numpy RuntimeError: Broken toolchain: cannot link a simple C program

Question

Writing my first Android app in Python and using Buildozer to package it. Because I will need to use numpy later on in the project, I tried packaging the following test code:

import numpy
import kivy
kivy.require('1.0.6')
from kivy.app import App
from kivy.uix.button import Button

class TestApp(App):
    def build(self):
        return Button(text='Hello World')

TestApp().run()

However, I got the following error:

Traceback (most recent call last):
  File "setup.py", line 251, in <module>
    setup_package()
  File "setup.py", line 243, in setup_package
    setup(**metadata)
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/core.py", line 169, in setup
    return old_setup(**new_attr)
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/python-installs/myapp/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/python-installs/myapp/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/python-installs/myapp/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/command/build_ext.py", line 59, in run
    self.run_command('build_src')
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/python-installs/myapp/lib/python2.7/distutils/cmd.py", line 326, in run_command
    self.distribution.run_command(command)
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/python-installs/myapp/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/command/build_src.py", line 153, in run
    self.build_sources()
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/command/build_src.py", line 164, in build_sources
    self.build_library_sources(*libname_info)
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/command/build_src.py", line 299, in build_library_sources
    sources = self.generate_sources(sources, (lib_name, build_info))
  File "/home/kivy/Desktop/cam/.buildozer/android/platform/build/build/other_builds/numpy/armeabi-v7a/numpy/numpy/distutils/command/build_src.py", line 386, in generate_sources
    source = func(extension, build_dir)
  File "numpy/core/setup.py", line 686, in get_mathlib_info
    raise RuntimeError("Broken toolchain: cannot link a simple C program")
RuntimeError: Broken toolchain: cannot link a simple C program


  STDERR:
# Command failed: /usr/bin/python -m pythonforandroid.toolchain create --dist_name=myapp --bootstrap=sdl2 --requirements=kivy,numpy --arch armeabi-v7a --copy-libs --color=always --storage-dir=/home/kivy/Desktop/cam/.buildozer/android/platform/build
# 
# Buildozer failed to execute the last command
# The error might be hidden in the log above this error
# Please read the full log, and search for it before
# raising an issue with buildozer itself.
# In case of a bug report, please add a full log with log_level = 2

Also, here is my buildozer.spec file:

title = My Application
package.name = myapp
package.domain = org.test
source.dir = .
source.include_exts = py,png,jpg,kv,atlas
version = 1.0

requirements = kivy,numpy

orientation = portrait
osx.kivy_version = 1.9.1
fullscreen = 0
android.api = 19
android.sdk = 20
android.ndk = 9c
android.arch = armeabi-v7a
log_level = 2
warn_on_root = 1

Note that when I removed "import numpy" from the python code and removed "numpy" from the requirements list in the buildozer.spec file, my code was packaged perfectly. I am running this on VM Virtual Box which had Buildozer pre-installed.

Also it is not just Numpy giving me this issue- OpenCV is giving me the exact same errors. Will make separate post for that if needed.

Answer 1

This issue is reported in Python for Android (p4a) project here, didn't knew it's actual for stable p4a. Nevertheless, by link you can find PR that fixes issue. I didn't test it, but different people say it works.

You can try to build numpy with this fix, here's what you'll need:

1. Make sure you clean all left from current building process with command:

   buildozer distclean

2. Clone p4a branch with fix using command:

   git clone -b p4a_numpy_fix https://github.com/mahomahomaho/python-for-android fix-numpy

3. Change your buildozer.spec to use this cloned version of p4a (use your actual path):

   p4a.source_dir = /home/ubuntu/p4a_numpy_fix

And run building apk again. If everything will work fine, you'll be able to build apk. If not you'll face another errors, no guarantees here :(