We Keep Coding

How do I avoid an ELFCLASS64 error when building Android 8 from source?

I have an old tablet I'm toying around with for the fun of it. I'm trying to build Android 8 from source just to tinker with it and see if I can install it on the tablet. I'm using Lubuntu 20.04 LTS.
So far, all I've done is set up my environment, sync to the android-8.1.0_r81 repo, and run m, all per the instructions here: https://source.android.com/setup
My tablet uses an ARMv7 processor, so when I ran lunch I chose aosp_arm-eng, which corresponds to a generic 32-bit ARMv7 processor.
However, when I run m, it eventually fails with the following error:
[ 0% 1/9730] build out/target/product/generic/obj/ETC/sepolicy_tests_intermediates/sepolicy_tests
FAILED: out/target/product/generic/obj/ETC/sepolicy_tests_intermediates/sepolicy_tests
/bin/bash -c "(python out/host/linux-x86/bin/sepolicy_tests.py -l out/host/linux-x86/lib64 -f out/target/product/generic/obj/ETC/plat_file_contexts_intermediates/plat_file_contexts -f out/target/product/generic/obj/ETC/nonplat_file_contexts_intermediates/nonplat_file_contexts -p out/target/product/generic/obj/ETC/sepolicy_intermediates/sepolicy ) && (touch out/target/product/generic/obj/ETC/sepolicy_tests_intermediates/sepolicy_tests )"
Traceback (most recent call last):
File "out/host/linux-x86/bin/sepolicy_tests.py", line 73, in <module>
pol = policy.Policy(options.policy, options.file_contexts, options.libpath)
File "/home/username/Android/Development/Oreo/out/host/linux-x86/bin/policy.py", line 255, in __init__
self.__InitLibsepolwrap(LibPath)
File "/home/username/Android/Development/Oreo/out/host/linux-x86/bin/policy.py", line 190, in __InitLibsepolwrap
lib = CDLL(LibPath + "/libsepolwrap.so")
File "/home/username/Android/Development/Oreo/prebuilts/python/linux-x86/2.7.5/lib/python2.7/ctypes/__init__.py", line 365, in __init__
self._handle = _dlopen(self._name, mode)
OSError: out/host/linux-x86/lib64/libsepolwrap.so: wrong ELF class: ELFCLASS64
...
From what I understand, the out directory is the output of the make command--out isn't in the original repo. I also understand (I think) that the wrong ELF class: ELFCLASS64 error means that the libsepolwrap.so library is expecting a 32-bit OS and getting a 64-bit one. What I don't understand is why libsepolwrap.so is expecting a 32-bit OS.
According to the docs,
A 64-bit environment is required for Android 2.3.x (Gingerbread) and higher versions, including the master branch. You can compile older versions on 32-bit systems.
Given that I haven't actually modified anything yet and I'm building a pure vanilla Android 8 ROM, I'm stumped as to how to even start trying to fix this.
Side Note: I am already aware that I can find a vanilla Android 8 ROM somewhere online; I'm more interested in building it myself so I can learn the process and have something to tinker with.

How to run paramiko demo_server.py?

https://raw.githubusercontent.com/paramiko/paramiko/master/demos/demo_server.py
I see the above demo_server of paramiko. But I don't see the instructions on how to run it. I run the following ./demo_server.py command. But once I run ssh robey#127.0.0.1 -p 2200, the server fails. Could anybody let me know the complete steps on how to run this example? Thanks.
$ python3 ./demo_server.py
Read key: 60733844cb5186657fdedaa22b5a57d5
Listening for connection ...
Got a connection!
*** Caught exception: <class 'ImportError'>: Unable to import a GSS-API / SSPI module!
Traceback (most recent call last):
File "./demo_server.py", line 140, in <module>
t = paramiko.Transport(client, gss_kex=DoGSSAPIKeyExchange)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/paramiko/transport.py", line 445, in __init__
self.kexgss_ctxt = GSSAuth("gssapi-keyex", gss_deleg_creds)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/paramiko/ssh_gss.py", line 107, in GSSAuth
raise ImportError("Unable to import a GSS-API / SSPI module!")
ImportError: Unable to import a GSS-API / SSPI module!
$ ssh robey#127.0.0.1 -p 2200
kex_exchange_identification: read: Connection reset by peer

I managed to get it to work, make sure to go through these steps (Thank you Sandeep for the pip insight), chances are you may be missing the Kerberos dependencies:
You may need to perform pip install gssapi in the CLI if that has not already been done (I'm using the Windows Command Prompt, Linux/WSL might need pip3 instead depending on your version of python)
From there you will need to import the gssapi library into the code at the top with the other imported libraries, so just call
import gssapi in demo_server.py
After running demo_server.py again, the CLI should eventually say something like it is missing files located in Program Files\ MIT\ Kerberos\ bin, as Kerberos is a dependency for gssapi, you can install it from here:
https://web.mit.edu/KERBEROS/dist/
Make sure you do custom install if you're not sure where it will be downloaded, so that you can set up the file location where the CLI says is missing in step 3 (Should automatically say Program Files\ MIT). I unchecked the boxes for auto-start and tickets, but not sure as to what your preferences may be. After all that, a computer restart is required.

ImportError: No module named _analog_swig

I am having issues getting python to import the _analog_swig gnuradio module in order to run gnuradio code on a Windows 8.1 64bit machine.
Some background: I am running Python 2.7.10 (installed in C:\Python27) and have installed the latest gnuradio binary (v3.7.11.1/v1.3 64-Bit Any CPU) from here: http://www.gcndevelopment.com/gnuradio/downloads.htm. I have installed gnuradio to C:\Program Files\GNURadio-3.7 .
I can run gnuradio companion and run flowgraphs from GRC successfully (which calls "C:\Program Files\GNURadio-3.7\bin\run_gr.bat" gnuradio-companion.py).
I have added & verified the following system variables are set:
Path: C:\Program Files\GNURadio-3.7\bin
PYTHONPATH: C:\Program Files\GNURadio-3.7\lib\site-packages
GRC_BLOCKS_PATH: C:\Program Files\GNURadio-3.7\share\gnuradio\grc\blocks
Now to the problem: If I run e.g. CMD and type:
python C:\test\top_block.py
I am returned the following ImportError:
File "C:\test\top_block.py", line 22, in <module>
from gnuradio import analog
File "C:\Program Files\GNURadio-3.7\lib\site-packages\gnuradio\analog\__init__.py", line 33, in <module>
from analog_swig import *
File "C:\Program Files\GNURadio-3.7\lib\site-packages\gnuradio\analog\analog_swig.py", line 17, in <module>
_analog_swig = swig_import_helper()
File "C:\Program Files\GNURadio-3.7\lib\site-packages\gnuradio\analog\analog_swig.py", line 16, in swig_import_helper
return importlib.import_module('_analog_swig')
File "C:\Python27\lib\importlib\__init__.py", line 37, in import_module
__import__(name)
ImportError: No module named _analog_swig
The folder content of C:\Program Files\GNURadio-3.7\lib\site-packages\gnuradio\analog is as follows:
Comparing this to the folder content on a linux machine, which has a working install of gnuradio that works with python as I want it:
The difference seems to be that the folder in windows contains only a _analog_swig.pyc file, whereas the folder in linux contains a _analog_swig_.so file.
Any idea why the _analog_swig module can apparently not be imported in windows?
My plan is to be able to run gnuradio code directly from my python interpreter and being able to create compiled gnuradio executables so any help on how this could be fixed is much appreciated.

I've been struggling with this for the past few days, but I finally figured it out. I was trying to run GnuRadio Companion generated code in IDLE and also in PyCharm. I kept failing miserably with this same error. I finally figured it out:
-As Flexo says, the PYD file (_analog_swig.pyd) is actually a Windows DLL. The error makes it sound like Python is not finding that file, but that is not at all what was happening. The PYD file, being a DLL, has dependencies itself. Python is able to find _analog_swig.pyd just fine, but it could not find the DEPENDENCIES of that library.
-To verify if that's what wrong in your installation, download and use DependencyWalker (Google it) to check if your system can find the dependencies to _analog_swig.pyd.
-The fix for me was to add the GnuRadio-3.7/bin folder to my PATH environment variable. Inside that folder are a number of DLLs that the _analog_swig.pyd library needs to load. If you don't have the folder in your PATH, the module will fail to load in Python and throw the error you see above.
-I see that you verified that this folder is in your PATH, so this is apparently not the same problem, although your symptoms are exactly the same as mine. i.e. the GRC code would run just fine when you start with "run_gr.bat", but not when you run from a normal CMD window.
Hopefully that helps someone else that wants to use GNURadio Python code on Windows.

Friend,
As you mentioned, the GNU Companion calls \bin\run_gr.bat gnuradio-companion.py. That batch script does quite a bit of work on windows environment variables (try opening it in a text editor if you're curious).
In a sense, the run_gr.bat script puts together a temporary, custom python workspace for gnuradio so it can import anything it needs. It receives python scripts to run in this environment as command line arguments; hence, you can use it to run any GNU radio python code you want in your windows command prompt. Generally, you would call
<gnuradio_install_path>\bin\run_gr.bat <gnu_radio_code>.py
To test your import, you can try
# test.py
from gnuradio import analog
try calling the following from the command prompt, in the test.py directory:
<gnuradio_install_path>\bin\run_gr.bat test.py

Debianzing a Python program to get a .deb [duplicate]

This question already has answers here:
Is there a standard way to create Debian packages for distributing Python programs?
(5 answers)
Closed 5 years ago.
Aim
To create an installable .deb file (or package). Which when clicked would install the software on a Linux machine and an icon would be put on the GNOME panel. So as to launch this application from there.
What I have referred to
I referred to two debianizing guides.
Guide 1
Guide 2
The first one had a video which was impossible to understand, partly because of the accent and partly because it was hopelessly outdated.(it was uploaded in 2007)
And the second one was completely text. I got till the 4th Step, Builds the package. But when I did it I got output that did not match what was given in the guide.
What I require
I have a simple python program. It takes your age and then prints back out if the age is below, equal to, or above 18 years. There is just one file and no other dependency for this program. And I want to build this into a .deb.
Specs
-Python 2.7
-Linux Mint
Edit
I followed the exact directory structure as you instructed as you. And replaced all myscript with cowsandbulls. The build completed and I got the Debian. When I installed it and then ran the command cowsandbulls from the terminal I got the following error:
Traceback (most recent call last):
File "/usr/bin/cowsandbulls", line 9, in <module>
load_entry_point('cowsandbulls==1.0', 'gui_scripts', 'cowsandbulls')()
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 337, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2311, in load_entry_point
return ep.load()
File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2017, in load
entry = __import__(self.module_name, globals(),globals(), ['__name__'])
ImportError: No module named cowsandbulls

I just tested stdeb (see https://pypi.python.org/pypi/stdeb), a Python package for turning any other Python package into a Debian package.
First I installed stdeb:
apt-get install python-stdeb
Then I made a simple script called myscript.py with the following contents:
def main():
print "Hello world, says myscript!"
# wait for input from the user
raw_input()
if __name__ == '__main__':
main()
Importantly, your directory structure should be:
somewhere/myscript/
setup.py
myscript/
__init__.py
myscript.py
In the setup.py file, you do something like:
import os
from setuptools import setup
from nvpy import nvpy
setup(
name = "myscript",
version = "1.0",
author = "Charl P. Botha",
author_email = "cpbotha#vxlabs.com",
description = "Demo of packaging a Python script as DEB",
license = "BSD",
url = "https://github.com/cpbotha/nvpy",
packages=['myscript'],
entry_points = {
'console_scripts' : ['myscript = myscript.myscript:main']
},
data_files = [
('share/applications/', ['vxlabs-myscript.desktop'])
],
classifiers=[
"License :: OSI Approved :: BSD License",
],
)
The console_scripts directive is important, and it'll create an executable script called my_script, which will be available system-wide after you install the resultant DEB. If your script uses something like tkinter or wxpython and has a graphical user interface, you should use gui_scripts instead of console_scripts.
The data_files directive will install a suitable desktop file into /usr/share/applications, so that you can also start myscript from your desktop environment. vxlabs-myscript.desktop looks like this:
[Desktop Entry]
Version=1.0
Type=Application
Name=myscript
Comment=Minimal stdeb example
# myscript should wait for user input at the end, else the terminal
# window will disappear immediately.
Exec=myscript
Icon=/usr/share/icons/gnome/48x48/apps/file-manager.png
Categories=Utility;
# desktop should run this in a terminal application
Terminal=true
StartupNotify=true
StartupWMClass=myscript
To build the DEB, you do the following in the top-level myscript:
python setup.py --command-packages=stdeb.command bdist_deb
Which will create a .deb in the deb_dist directory.
After having installed the DEB I created like this, I could run myscript from the command-line, and I could also invoke it from my desktop environment.
Here's a GitHub repository with the example code above: https://github.com/cpbotha/stdeb-minimal-example

The right way of building a deb package is using dpkg-buildpackage, but sometimes it is a little bit complicated. Instead you can use dpkg -b <folder> and it will create your Debian package.
These are the basics for creating a Debian package with dpkg -b <folder> with any binary or with any kind of script that runs automatically without needing manual compilation (Python, Bash, Pearl, and Ruby):
Create the files and folders in order to recreate the following structure:
ProgramName-Version/
ProgramName-Version/DEBIAN
ProgramName-Version/DEBIAN/control
ProgramName-Version/usr/
ProgramName-Version/usr/bin/
ProgramName-Version/usr/bin/your_script
The scripts placed at /usr/bin/ are directly called from the terminal. Note that I didn't add an extension to the script.
Also, you can notice that the structure of the deb package will be the structure of the program once it's installed. So if you follow this logic if your program has a single file, you can directly place it under ProgramName-Version/usr/bin/your_script, but if you have multiple files, you should place them under ProgramName-Version/usr/share/ProgramName/all your files and place only one file under /usr/bin/ that will call your scripts from /usr/share/ProgramName/.
Change all the folder permission to root:
chown root:root -R /path/to/ProgramName-Version
Change the script's permissions:
chmod 0755 /path/to/the/script
Finally, you can run: dpkg -b /path/to/the/ProgramName-Version and your deb package will be created! (You can also add the post/pre inst scripts and everything you want; it works like a normal Debian package.)
Here is an example of the control file. You only need to copy-paste it in to an empty file called "control" and put it in the DEBIAN folder.
Package: ProgramName
Version: VERSION
Architecture: all
Maintainer: YOUR NAME <EMAIL>
Depends: python2.7, etc , etc,
Installed-Size: in_kb
Homepage: http://foo.com
Description: Here you can put a one line description. This is the short Description.
Here you put the long description, indented by 1 space.
If you want to build using dpkg -b <folder> you can use this program that will do everything with one command. If you regularly build packages, it is a pain to do all the stuff that I mentioned!
*The guide was taken from Basics of Debian Packages.

problem compiling libjingle

I downloaded and installed libjingle-0.5.2.zip, and according to the README also downloaded and installed swtoolkit.0.9.1.zip, scons-local-2.1.0.alpha.20101125.tar.gz, and expat-2.0.1.tar.gz, and got nrtp by cvs download. After overwriting my Makefile twice, attempting to follow the rather poorly-written README, I came up with the following Makefile that almost works:
# First, make sure the SCONS_DIR environment variable is set correctly.
SCONS_DIR ?= /usr/src/scons-local/scons-local-2.1.0.alpha.20101125/
#SCONS_DIR ?= /usr/src/scons-local/
export
default: build
# Second, run talk/third_party/expat-2.0.1/configure...
talk/third_party/expat-2.0.1/Makefile:
cd talk/third_party/expat-2.0.1 && ./configure
# ...and talk/third_party/srtp/configure.
talk/third_party/srtp/Makefile:
cd talk/third_party/srtp && ./configure
# Third, go to the talk/ directory and run $path_to_swtoolkit/hammer.sh. Run
# $path_to_swtoolkit/hammer.sh --help for information on how to build for
# different modes.
build: talk/third_party/expat-2.0.1/Makefile talk/third_party/srtp/Makefile
cd talk && ../../swtoolkit/hammer.sh
help:
../swtoolkit/hammer.sh --help
However, make gives me the following errors:
jcomeau#intrepid:/usr/src/libjingle-0.5.2$ make
cd talk && ../../swtoolkit/hammer.sh
*** Error loading site_init file './../../swtoolkit/site_scons/site_init.py':
AttributeError: 'Dir' object has no attribute 'endswith':
File "/usr/src/scons-local/scons-local-2.1.0.alpha.20101125/SCons/Script/Main.py", line 1338:
_exec_main(parser, values)
File "/usr/src/scons-local/scons-local-2.1.0.alpha.20101125/SCons/Script/Main.py", line 1302:
_main(parser)
File "/usr/src/scons-local/scons-local-2.1.0.alpha.20101125/SCons/Script/Main.py", line 929:
_load_site_scons_dir(d.path, options.site_dir)
File "/usr/src/scons-local/scons-local-2.1.0.alpha.20101125/SCons/Script/Main.py", line 719:
exec fp in site_m
File "./../../swtoolkit/site_scons/site_init.py", line 455:
SiteInitMain()
File "./../../swtoolkit/site_scons/site_init.py", line 451:
SCons.Node.FS.get_default_fs().SConstruct_dir, None)
File "/usr/src/scons-local/scons-local-2.1.0.alpha.20101125/SCons/Script/Main.py", line 677:
site_dir = os.path.join(topdir, site_dir_name)
File "/usr/lib/python2.6/posixpath.py", line 67:
elif path == '' or path.endswith('/'):
make: *** [build] Error 2
I'm guessing that something new (a 'Dir' object being where a POSIX path string is expected) in one of the packages is breaking the build process, but which one? There are just too many layers of cruft here for me to follow. For sure I could just keep trying older packages, particularly for swtoolkit and scons, but if anyone here has successfully compiled libjingle and could prod me in the right direction, I'd appreciate it.

I'm not familiar with the project, but think I have a fix to get you past that point. You need to cast those Dir instances using str() in swtoolkit/site_scons/site_init.py. That way they can safely be evaluated by path.endswith('/'). Odd that such an issue would exist for very long in the main part of the build infrastructure:
Line 330:
SCons.Script.Main._load_site_scons_dir(
str(SCons.Node.FS.get_default_fs().SConstruct_dir), site_dir)
Line 450:
SCons.Script.Main._load_site_scons_dir(
str(SCons.Node.FS.get_default_fs().SConstruct_dir), None)

I did following to build libjingle :
Building LibJingle for Linux
How to Build
Libjingle is built with swtoolkit ( http://code.google.com/p/swtoolkit/), which
is a set of extensions to the open-source SCons build tool ( http://www.scons.org).
First, install Python 2.4 or later from http://www.python.org/.
Please note that since swtoolkit only works with Python 2.x, you will
not be able to use Python 3.x.
Second, install the stand alone scons-local package 2.0.0 or later from
http://www.scons.org/download.php and set an environment variable,
SCONS_DIR, to point to the directory containing SCons, for example,
/src/libjingle/scons-local/scons-local-2.0.0.final.0/.
Third, install swtoolkit from http://code.google.com/p/swtoolkit/.
Finally, Libjingle depends on two open-source projects, expat and srtp.
Download expat from http://sourceforge.net/projects/expat/ to
talk/third_party/expat-2.0.1/. Follow the instructions at
http://sourceforge.net/projects/srtp/develop to download latest srtp to
talk/third_party/srtp. Note that srtp-1.4.4 does not work since it misses
the extensions used by Libjingle.
If you put expat or srtp in a different directory, you need to edit
talk/libjingle.scons correspondingly.
2.1 Build Libjingle under Linux or OS X
First, make sure the SCONS_DIR environment variable is set correctly.
Second, run talk/third_party/expat-2.0.1/configure and
talk/third_party/srtp/configure.
Third, go to the talk/ directory and run $path_to_swtoolkit/hammer.sh. Run
$path_to_swtoolkit/hammer.sh --help for information on how to build for
different modes.
Other than above given steps, See following as reference
Set SCONS_DIR Path
export SCONS_DIR=/home/esumit/libjingle/libjingle-0.5.2/talk/third_party/scons-local/scons-local-2.0.1
Install libasound2-dev Lib to compile libJingle, otherwise you will encounter errors.
sudo apt-get install libasound2-dev
Download SRTP using the following command. If it asks for a passowrd, just hit Enter.
cvs -z3 -d:pserver:anonymous#srtp.cvs.sourceforge.net:/cvsroot/srtp co -P srtp
Possible components in LibJingle Directory
libjingle-0.5.2/talk/third_party$ ls
expat-2.0.1 libudev scons-local srtp swtoolkit
Execute following command to build LibJingle
libjingle-0.5.2/talk$ ./third_party/swtoolkit/hammer.sh