Develop Reference

CrossCompilie python code for raspberry pi

I found issues on installing a cross compiler on my Ubuntu19.04 64 bit machine. I would like to cross compile python code into executable for my raspberry pi 3 model b+ running Debian Stretch.
I followed many guides, none of them worked. I am actually following https://github.com/Yadoms/yadoms/wiki/Cross-compile-for-raspberry-PI
I followed step of the above written guide:
- Setup Environment
- Install cross compiler
- Boost 1.64
- Python
On the last part (Python) it fails to execute the last instruction.
$ CC=arm-linux-gnueabihf-gcc CXX=arm-linux-gnueabihf-g++ AR=arm-linux-gnueabihf-ar RANLIB=arm-linux-gnueabihf-ranlib ./configure --host=arm-linux-gnueabihf --target=arm-linux-gnueabihf --build=x86_64-linux-gnu --prefix=$HOME/Desktop/rapsberry/depsBuild/python --disable-ipv6 ac_cv_file__dev_ptmx=no ac_cv_file__dev_ptc=no ac_cv_have_long_long_format=yes --enable-shared
output:
checking build system type... x86_64-pc-linux-gnu
checking host system type... arm-unknown-linux-gnueabihf
checking for python3.7... python3.7
checking for python interpreter for cross build... python3.7
checking for --enable-universalsdk... no
checking for --with-universal-archs... no
checking MACHDEP... checking for --without-gcc... no
checking for --with-icc... no
checking for arm-linux-gnueabihf-gcc... arm-linux-gnueabihf-gcc
checking whether the C compiler works... no
configure: error: in `/home/slr/Desktop/raspberry/boost_1_64_0/Python-3.7.5':
configure: error: C compiler cannot create executables
See `config.log' for more details
and then:
$ make HOSTPYTHON=$HOME/Desktop/raspberry/depsBuild/pythonhost/python HOSTPGEN=$HOME/Desktop/raspberry/depsBuild/pythonhost/Parser/pgen BLDSHARED="arm-linux-gnueabihf-gcc -shared" CROSS-COMPILE=arm-linux-gnueabihf- CROSS_COMPILE_TARGET=yes HOSTARCH=arm-linux BUILDARCH=arm-linux-gnueabihf
output:
make: *** No targets specified and no makefile found. Stop.
I need python3 for my purpose.
I am really stuck in this problem, could someone have some idea? I tried also with QEMU and Docker (https://raspberrypi.stackexchange.com/questions/109488/building-a-virtual-machine-with-the-img-file-of-the-raspberry-pi-stretch) and both of them failed in compiling my target code:
gcc: internal compiler error
My code is pretty long ( Some thousand of lines ), while small codes successfully works. Thanks in advice.

There seems to be something wrong with the toolchain you're using, or with the way you're invoking the Python configure script.
Either way, it's impossible to debug without seeing your exact setup, so I'll start from scratch here.
I'm in the process of documenting a similar project here: Raspberry Pi C++ development.
Toolchain
The toolchains in the raspberrypi/tools repository are pretty old. I usually just build a new one using Crosstool-NG (which is what the raspberrypi/tools toolchains were built with as well, IIRC).
I used the armv8-rpi3-linux-gnueabihf sample.
You can of course build it yourself, but this can take quite some time, so you can also download the one I built from Docker Hub (see later).
You can find more information about how it was built here: Detailed information about configuring and building toolchains
.
Compiling Python for the build system
In order to cross-compile a Python module, you need the same version of Python twice: once for your build system (the computer you're building on) and once for the host system (the Raspberry Pi you're building for).
Both will be compiled from source, to ensure that they are exactly the same version.
The build Python will just be used for cross-compiling the host Python, so we won't enable optimizations and optional modules.
This is the script I used: python-build.sh
You need OpenSSL, Zlib and libffi for pip to work. I built them from source as well, but you could of course install them using your package manager (you need the -dev versions).
Again, you can find the install scripts I used here.
Cross-compiling Python for the host system
Before you can cross-compile Python for the Raspberry Pi, you'll have to cross-compile its dependencies. A detailed explanation can be found here: Cross-compiling the dependencies.
You can find the scripts in the same folder on GitHub I linked to earlier, for instance, python.sh.
There are some caveats when cross-compiling, you need a pkg-config with the right prefix that looks for the required libraries in the sysroot of your cross-compilation, instead of in your build system's library folders. You also have to specify the include directories and library folders when calling the configure script.
All of this is handled by this Dockerfile and the scripts in the same folder.
Crossenv
The easiest way to cross-compile Python modules is to use Crossenv. The instructions can be found in the README of the GitHub page.
When everything is set up, you can run python setup.py bdist_wheel.
Example
As an example, you can follow these steps to compile a simple Python module using Cython:
1. Pull the toolchain and the cross-compiled Python from Docker hub
This is an image that contains the cross-compilation toolchain, native and cross-compiled Python, as well as Crossenv.
docker pull tttapa/rpi3-armv8-python-opencv-cross
2. Create the Python file to compile and setup.py to build it
Create these two files:
helloworld.py
print("Hello, World")
setup.py
from setuptools import setup
from Cython.Build import cythonize
from sys import version_info
setup(
name='helloworld',
version='0.0.1',
ext_modules = cythonize("helloworld.py", language_level=version_info[0])
)
3. Create a script that builds the Python module
This script will be run inside of the Docker container.
build.sh
#!/usr/bin/env bash
set -e
cd /tmp/workdir
source "$HOME/crossenv/bin/activate"
build-pip install cython
cross-pip install wheel
python setup.py bdist_wheel
4. Start the Docker container and build the module
Run the following command in the same folder where you created the three files.
docker run --rm -v "$PWD:/tmp/workdir" \
tttapa/rpi3-armv8-python-opencv-cross \
bash "/tmp/workdir/build.sh"
When the build is complete, you'll find a file dist/helloworld-0.0.1-cp38-cp38-linux_arm.whl, which you can install using pip install helloworld-0.0.1-cp38-cp38-linux_arm.whl on the Raspberry Py. You'll also find the helloworld.c file generated by Cython.
To be able to run it, you'll probably have to install the cross-compiled libraries and Python itself to the RPi. You can do this by copying everything inside of ~/RPi-staging (inside of the Docker container) to the Pi's root folder /.

Installing jedi-vim fails: vim says wrongly that +python is not compiled

I am trying to install jedi-vim. I am doing this at work - so I have to use gVim in Windows. I have already read several other posts in this forum. This has somehow made me smarter but still does not solve my problem.
I did the following things:
installed Pathogen
cloned jedi vim from https://github.com/davidhalter/jedi-vim.git and copied it to the bundle/ folder in the vim-dir.
Now, when I open a *.py-file vim always tells me
jedi-vim requires vim compiled with +python
but ':version' tells me that it's compiled with +python/dyn and +python3/dyn.
So what is the problem?
Additional infos:
vim version: 7.4
When I use ctrl+space to autocomplete a python key word, it tells me:
Error detected while processing function jedi#completions: line 1: E492: Not an editor command: Python jedi_vim.completions()
Error detected while processing function jedi#completions: line 1: E492: Not an editor command: Python jedi_vim.completions()
Press ENTER or type command to continue

I'm not sure if your are still experiencing the same issue, but after looking around I found this blog post that solved the problem for me. Essentially, it's just about re-installing vim (don't delete any config files) and then reinstalling from the source at the vim mercurial repo with the right flags. There might be a shorter/simpler version of doing this, but after trying back and forth many solutions, this one was the only one that worked:
Compiling Vim with Python and Ruby support on Ubuntu
These are the steps:
Check if Vim is compiled with Python:
$ vim --version | ack '(python)'
Remove Vim version installed:
$ sudo apt-get remove vim-common vim-runtime
Install dependencies needed to compile Vim:
$ sudo apt-get build-dep vim
Clone Vim repository, compile it and install the new version:
$ hg clone https://vim.googlecode.com/hg/ vim
$ cd vim
$ ./configure --enable-pythoninterp
$ make
$ sudo make install

+python/dyn means that Python support isn't statically compiled it, it's loaded dynamically when needed at runtime.
This is described in the python-dynamic help section:
On MS-Windows the Python library can be loaded dynamically. The |:version| output then includes |+python/dyn|.
This means that Vim will search for the Python DLL file only when needed.
When you don't use the Python interface you don't need it, thus you can use
Vim without this DLL file.
To use the Python interface the Python DLL must be in your search path. In a console window type "path" to see what directories are used.
The name of the DLL must match the Python version Vim was compiled with.
Currently the name is "python24.dll". That is for Python 2.4. To know for
sure edit "gvim.exe" and search for "python\d*.dll\c".
(Don't worry about the 2.4 there; I just happened to find docs from a few years ago. Read the help in your own copy of vim—or, better, do what the last paragraph says.)
So, either you don't have Python, you have the wrong version of Python, it's not on your %PATH%, vim is searching for it incorrectly, or it's failing to load.

At that time the problem was another one. I mixed up the architectures for vim and python - I used vim64Bit, but pyhton for 32bit.
I repaired that already some time ago but the other day I had to restart my computer and do some microsoft-Updates.
Unfortunately my vim (7.4) was totally broken. I had to re-set my home-dir. Then at least my vimrc was accessible again, but still my jedi in vim does not work.
Python is available in vim but still jedi does not seem to load correctly.
When I type "len(" in the beginning of a .py-file, at the place where arguments should be explained there are some strange characters, similar to this:
==jedi=0, == (_object_*) ==jedi==
When I type "self.", it says "unknown function: pythoncomplete#Complete"
I think it's only a configuration-issue, because it worked before the reboot.
Jedi is installed systemwide (with pip). If I try to install it "again", pip says that jedi is already installed.
I would appreciate your help very much ;-)

Python GDal installation

Having some problems with Gdal installation with python 2.7 on Windows 7 32bit. I am running MSVC 2010. I have followed the instruction from the blog website
http://cartometric.com/blog/2011/10/17/install-gdal-on-windows/
The installation is fine. At the end of it, I am able to run ogr2ogr in the MS-DOS and have gotten the similar screen as listed in the blog.
However, when I am trying to use the command "import osgeo" on the Python IDLE GUI shell. A series of error message is released, reading like the following
"DLL error:.........."
I believe that this might mean that the python binding is of wrong version. I have cleared up my installation by removing the following: Python-Gdal binding, Gdal, Python 2.7
After removing them, I have retried my installation with Python 3.2.3 instead and loaded the Gdal package and python binding accordingly. However, the same error returns.
Is there any intermediate steps that I could take to verify the installation. Any other advice I could have to have the bindings installed? Or is my reinstallation method correct?
I have tried to install FWTools too. It doesnt seem to work either. I have run the Python shell from EV-shell and type in "import osgeo". Have gotten the message "no module exist...."
Thanks

Get the precompiled gdal from here:
http://www.lfd.uci.edu/~gohlke/pythonlibs/#gdal
I have some other notes on setting up postgres and postgis 2.0 here if you need it:
http://monkut.webfactional.com/blog/archive/2012/5/2/using-django-14-with-gdal-19-and-postgis-20/

py2app built app displays `ERROR: pygame.macosx import FAILED` on other machines

Trying to build an app on the Mac using py2app. Got everything working fine on my machine, but when moving the app to another, it crashes and the console displays this error.
ERROR: pygame.macosx import FAILED
Anybody have a solution to this?

Found the problem and solution after many hours. Turns out other people have experienced similar problems and their articles were quite helpful:
http://b.atcg.us/blog/2010/04/13/py2app-hell-the-first.html
http://www.vijayp.ca/blog/?p=62
In case someone else runs into the issue, this particular problem was caused because the Python framework was not being bundled into the application. You can confirm this by right-clicking your app to view package contents, then proceed to Contents/Frameworks/. If Python.framework is not there, it should be.
Be sure to download Python -
My first issue was reliance on Apple's build in Python package. Don't use this. You need to install your own version of python. Go to http://www.python.org/download/releases/, find a version (I stuck with 2.6), download the gzip (not the mac package), and install with the following if you are running Snow Leopard:
./configure --enable-framework MACOSX_DEPLOYMENT_TARGET=10.6 --with-universal-archs=intel --enable-universalsdk=/
make
sudo make install
Adjust Paths, Install Packages - From here there you need to adjust your paths to ensure you are using your custom-installed version. From here, I reinstalled the following packages - this turned out to be a dependency nightmare so I'm including the version numbers as well:
py2app 0.5.2
macholib 1.3
modulegraph .8.0
If these packages actually worked, you should be able to build and run your app now. Unfortunately, they don't. I'll go into the errors and my hacked solutions in a bit, but there's some settings in the build file that need to be made first.
First the setup.py file should like a little somethin' like this:
setup.py
from setuptools import setup
APP = ['Game.py']
DATA_FILES = ['data']
OPTIONS = {
"argv_emulation": False,
"compressed" : True,
"optimize":2,
"iconfile":'data/game.icns',
}
setup(
app=APP,
data_files=DATA_FILES,
options={'py2app': OPTIONS},
)
then to be extra safe, I use a shell script to call this.
build.sh
## Remove previous builds. Start with clean slate.
rm -rf build dist
## Force python into 32 bit mode.
export VERSIONER_PYTHON_PREFER_32_BIT=yes
## Force build with custom installed python
/Library/Frameworks/Python.framework/Versions/2.6/bin/python setup.py py2app
Running build.sh should compile the app. If it does not compile, I have good news -- it's not your fault. Due to glitches in the libraries, you may run into some (or all) of the following:
Potential Problems
If the build script fails, scan the traceback for some of the following keywords:
pygame not found - basic path problem in py2app. Add...
sys.path.insert(0, os.path.join(os.getcwd(), 'lib', 'python2.6','lib-dynload')) ## Added to fix dynlib bug
after the import statements in boot_app.py in the py2app lib.
pythonNone - This appears to be a bug in the macho package where it cannot determine the version number of your python build. To solve this, I added the following lines to build_app.py in py2app.
## Add these two lines...
if not info["version"]:
info["version"] = "2.6"
## Before this line. (line 941 in method copy_python_framework() at time of writing)
pydir = 'python%s'%(info['version'])
No such file or directory...Python.framework/[lib|include] - py2app is simply looking for directories that exist deeper in the file system tree. Go to the Python.framework directory and symlink up the place...
cd /Library/Frameworks/Python.framework
sudo ln -s Versions/Current/include/ include
sudo ln -s Versions/Current/lib lib
That should do it! - These steps created a compiled app that worked on other intel machines.

Thank you for posting what you found!
I had a similar problem. I tried various combinations of what you suggested, and isolated the single issue for me to be the bug in boot_app.py which you identify above.
Once I added the one-line fix to boot_app.py which you identify above, everything worked, even using the pre-installed Apple build of python (version 2.6.1).
I should note that when I say "everything worked," I really mean building a py2app app for actual distribution, i.e. using the normal command:
python setup.py py2app
The "alias" mode. i.e.
python setup.py py2app -A
which the py2app documentation suggests for use during development, still does not work for me (with the same module not found error). But better the actual distribution build working than nothing at all! Again, thanks.

How to install PySide v0.3.1 on Mac OS X?

I'm trying to install PySide v0.3.1 in Mac OS X, for Qt development in python.
As a pre-requisite, I have installed CMake and the Qt SDK.
I have gone through the documentation and come up with the following installation script:
export PYSIDE_BASE_DIR="<my_dir>"
export APIEXTRACTOR_DIR="$PYSIDE_BASE_DIR/apiextractor-0.5.1"
export GENERATORRUNNER_DIR="$PYSIDE_BASE_DIR/generatorrunner-0.4.2"
export SHIBOKEN_DIR="$PYSIDE_BASE_DIR/shiboken-0.3.1"
export PYSIDE_DIR="$PYSIDE_BASE_DIR/pyside-qt4.6+0.3.1"
export PYSIDE_TOOLS_DIR="$PYSIDE_BASE_DIR/pyside-tools-0.1.3"
pushd .
cd $APIEXTRACTOR_DIR
cmake .
cd $GENERATORRUNNER_DIR
cmake -DApiExtractor_DIR=$APIEXTRACTOR_DIR .
cd $SHIBOKEN_DIR
cmake -DApiExtractor_DIR=$APIEXTRACTOR_DIR -DGeneratorRunner_DIR=$GENERATORRUNNER_DIR .
cd $PYSIDE_DIR
cmake -DShiboken_DIR=$SHIBOKEN_DIR/libshiboken -DGENERATOR=$GENERATORRUNNER_DIR .
cd $PYSIDE_TOOLS_DIR
cmake .
popd
Now, I don't know if this installation script is ok, but apparently everything works fine. Each component (apiextractor, generatorrunner, shiboken, pyside-qt and pyside-tools) gets compiled into its own directory.
The problem is that I don't quite understand how PySide gets into the system's python environment. In fact, when I start a python shell, I cannot import PySide:
>>> import PySide
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named PySide
Note: I am aware of the Installing PySide - OSX question, but that question is not relevant anymore, because it is about a specific a dependency on the Boost libraries, but with version 0.3.0 PySide moved from a Boost based source code to a CPython one.

I don't have any MacOS experience but assuming it's similar to any *nix, let's go:
About the script: Isn't it missing some "make, make install" commands? The version you posted just run cmake to configure the build. Also for testing, I set -DCMAKE_INSTALL_PREFIX= for all modules. That way everything is installed in the same place and CMake takes care of finding them for me, as long as I used the same install prefix for each one. The directory layout in your script is quite complicated and mixes build and source directories.
About finding PySide: once everything is properly compiled and installed, the directory where the "PySide" directory was installed must be available in the PYTHONPATH variable. In the example below,
Here's a simple version of a build script(works on Ubuntu):
#!/bin/bash
BUILD_ROOT=/tmp/pyside-build
INSTALL_PREFIX=/tmp/sandbox
function build_module {
cd $BUILD_ROOT
echo Cloning project $1 from url $2
git clone --depth 1 $2 $BUILD_ROOT/$1
BUILD_DIR=$BUILD_ROOT/$1/build
mkdir -p $BUILD_DIR
cd $BUILD_DIR
echo Configuring $1 build.
cmake -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX ..
echo Configured $1. Starting build.
make LD_LIBRARY_PATH=$INSTALL_PREFIX/lib
echo Built $1. Installing.
make install
echo Successfully built and installed $1
}
rm -rf $BUILD_ROOT
mkdir -p $BUILD_ROOT
build_module apiextractor git://gitorious.org/pyside/apiextractor.git
build_module generatorrunner git://gitorious.org/pyside/generatorrunner.git
build_module shiboken git://gitorious.org/pyside/shiboken.git
build_module pyside-shiboken git://gitorious.org/pyside/pyside-shiboken.git
Run it and wait a while (Qt is quite big). :)
This script will download all packages into /tmp/pyside-build, build each one in its own "build" directory and install everything into /tmp/sandbox. Then, I just had to set PYTHONPATH to /tmp/sandbox/lib/python2.6/site-packages and PySide worked fine.

In answer to the original post...
What your script would have done is generate the necessary build files to build the pyside bindings, but it wouldn't have done the build itself. To do the build itself you'd need to execute a 'make', then a 'make install' in each of the build directories.
I've gotten most of the way through getting pyside 0.3.1 up and running on the Mac (SnowLeopard 10.6.3), but am hung up on the final compile step. My script is a bit less straightforward than yours, but in essence similar.
I have run into and worked around a number of problems to get to the final compile, and am hoping that I can help some folks along with the solutions/workarounds I've devised. Also, maybe collectively we can figure out how to get through the final step.
I'm going to include the build script that I'm using, and the log of the changes I had to make in the distro to get it running. But first, the step that I'm stuck on... mainly, I don't understand the error message, and the requested file doesn't seem to exist...
I hope this will help move support for the mac along...
I can't post this directly on stack overflow since its too long, so here is the link to the post on the mailing list over at pyside.
http://lists.openbossa.org/pipermail/pyside/2010-June/000812.html

While it's a been couple months since this question originally was asked I ran across the official PySide build script repo at:
http://qt.gitorious.org/pyside/buildscripts
The README covers the build process:
http://qt.gitorious.org/pyside/buildscripts/blobs/master/README
It seems to be fairly automatic with my only caveat so far being that it pulls down libxslt via brew - I can't say authoritatively if libxslt shipped with Snow Leopard or not - but it's definitely in Lion by default.
Seemingly the only manual install step is putting cmake on your system.