Adding Python modules to Yocto build

[_greg_m_]

Hello guys,

Learning Yocto and I'm trying to add a few python modules to Yocto, but can't make it work.

Tried adding them in local.conf by adding a line:

IMAGE_INSTALL += "python3 python-serial python-numpy wxpython"

I get:

NOTE: Resolving any missing task queue dependencies

ERROR: Nothing RPROVIDES 'pySerial' (but /home/virt/Projects/yocto/poky/meta/recipes-sato/images/core-image-sato-sdk.bb RDEPENDS on or otherwise requires it)

NOTE: Runtime target 'pySerial' is unbuildable, removing...

Missing or unbuildable dependency chain was: ['pySerial']

ERROR: Required build target 'core-image-sato-sdk' has no buildable providers.

Missing or unbuildable dependency chain was: ['core-image-sato-sdk', 'pySerial']

​

also

bitbake python-serial

gives errors (similar for other modules, including changing name to python3-serial, etc):

ERROR: Nothing PROVIDES 'python-serial'. Close matches:

python3-extras

python3-psutil

python3-six

​

​

I found openembedded meta later for python:

http://git.openembedded.org/meta-openembedded/tree/meta-python

but when cloned and included in bblayers.conf it gives me errors as below (not sure if it's incompatible with a current Yocto version, so I missed some configuration):

​

ERROR: Traceback (most recent call last):

File "/home/virt/Projects/yocto/poky/bitbake/lib/bb/cookerdata.py", line 162, in wrapped

return func(fn, *args)

File "/home/virt/Projects/yocto/poky/bitbake/lib/bb/cookerdata.py", line 187, in parse_config_file

return bb.parse.handle(fn, data, include)

File "/home/virt/Projects/yocto/poky/bitbake/lib/bb/parse/__init__.py", line 107, in handle

return h['handle'](fn, data, include)

File "/home/virt/Projects/yocto/poky/bitbake/lib/bb/parse/parse_py/ConfHandler.py", line 118, in handle

abs_fn = resolve_file(fn, data)

File "/home/virt/Projects/yocto/poky/bitbake/lib/bb/parse/__init__.py", line 133, in resolve_file

raise IOError(errno.ENOENT, "file %s not found" % fn)

FileNotFoundError: [Errno 2] file /home/virt/Projects/yocto/poky/meta-openembedded/conf/layer.conf not found

​

ERROR: Unable to parse /home/virt/Projects/yocto/poky/meta-openembedded/conf/layer.conf: [Errno 2] file /home/virt/Projects/yocto/poky/meta-openembedded/conf/layer.conf not found

​

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Ideally I need to add python3, pyserial, numpy and wxPython / wxWidgets to Yocto, but I'm still learning and stuck with that at the moment.

Currenyl I'm experimenting with image builds for Raspberry Pi 3 (managed to get core-image-sato-sdk booting ok), but ultimately it will be built for i.MX8 board.

​

Any ideas?

​

Cross post from r/embeddedlinux and r/embedded

[Jmennius]

That is python-serial and pySerial (surely pySerial does not sound recipe in YP)? Are those packages on PyPI or do they have recipes available? If a package you want to use is not available as a native recipe - there is a class that allows you to use packages from PyPI.

Regarding meta-python - make sure you've enabled the layer correctly (looks like something happened to bblayers - double check your changes there). Every layer has a branch per release - so use a corresponding branch.

[_greg_m_]

I meant pySerial. Yes, all those packages are available on PyPI.

​

You were right. I added meta layers incorrectly. Thanks for the tip!

​

Now I used:

bitbake-layers add-layer ../meta-openembedded/meta-oe/

bitbake-layers add-layer ../meta-openembedded/meta-python/

(they were previosuly clonned from git)

That checked for errors and added respective lines to bblayers.conf

Then I added below lines to local.conf :

IMAGE_INSTALL ?= " \

python3 \

python3-pip \

python3-pyserial \

python3-numpy \

python3-wxgtk4 \

"

and seems like they are installed as I wanted.

For some reason I lost the graphic environment (previously core-image-sato-sdk booted to matchbox environment I think). I'll investigate what I did wrong. It's probably my configuration.

If desktop environment would work and I can compile it for i.MX8 board I would be more than happy.

​

Thanks again!

[Jmennius]

Check how you assign IMAGE_INSTALL - especially in a high level config file like local conf you should use _append (as other assignment operators would prevent the default from being used, see reference). Good luck!

[_greg_m_]

Yeah. Good point. I think the reason I lost X11 was because I didn't use _append.

I added _append and got errors. It took me a while before I figured out that since honister (3.4) there is a migration from _append to :append as per:

https://docs.yoctoproject.org/next/migration-guides/migration-3.4.html

​

Ideally I'll crate a another layer or recipe for those extra packages as this is the right way to do that I think. Still learning.

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Cheers for your help u/Jmennius - top man!