Re: Python dependency missing during RPM build

[Miro Hrončok]

On 11/19/20 6:02 PM, Richard W.M. Jones wrote:
>  It's not a big deal because I added the Python Requires: line by
> hand,
>  but I want to make sure I understand why it happens and whether
>  there's an easy fix.
>  
>     https://koji.fedoraproject.org/koji/taskinfo?taskID=55889416
>     https://src.fedoraproject.org/rpms/nbdkit/blob/master/f/nbdkit.spec#_475
>  
>  This subpackage contains a Python file:
>  
>     $ rpm -qlp ./nbdkit-S3-plugin-1.23.9-1.fc34.x86_64.rpm
>     /usr/lib64/nbdkit/plugins/nbdkit-S3-plugin       <--- this one
>     /usr/share/doc/nbdkit-S3-plugin
>     /usr/share/doc/nbdkit-S3-plugin/README
>     /usr/share/licenses/nbdkit-S3-plugin
>     /usr/share/licenses/nbdkit-S3-plugin/LICENSE
>     /usr/share/man/man1/nbdkit-S3-plugin.1.gz
>  
>  The automatically generated dependencies don't pick up the need for
>  python3-boto3.
>  
>     $ grep ^import nbdkit-S3-plugin
>     import nbdkit
>     import boto3
>  
>     $ rpm -qRp ./nbdkit-S3-plugin-1.23.9-1.fc34.x86_64.rpm
>     /usr/sbin/nbdkit
>     nbdkit-python-plugin >= 1.22
>     rpmlib(CompressedFileNames) <= 3.0.4-1
>     rpmlib(FileDigests) <= 4.6.0-1
>     rpmlib(PayloadFilesHavePrefix) <= 4.0-1
>     rpmlib(PayloadIsZstd) <= 5.4.18-1
>  
>  (As I said above, I added it explicitly, which is why the RPM built in
>  Koji above _does_ contain the boto3 dependency).
>  
>  Now admittedly the Python file doesn't end in .py and doesn't have a
>  python shebang at the top.  But:
>  
>     $ file nbdkit-S3-plugin
>     nbdkit-S3-plugin: Python script, ASCII text executable
>  
>  which seems as if it matches the %__python_magic regexp in
>  /usr/lib/rpm/fileattrs/python.attr.  So perhaps it _ought_ to work and
>  something is wrong on the machine I'm using to reproduce this?
>  
>  Alternatively is there another way to tell the dependency generator to
>  take a special look at this file? 
There are three dependency generators for Python and neither of them does what 
you ask here.


/usr/lib/rpm/fileattrs/python.attr

This file makes sure that files installed into /usr/lib(64)/pythonX.Y require 
python(abi) = X.Y.


/usr/lib/rpm/fileattrs/pythondist.attr

This file makes sure that Python packages (upstream term) require other Python 
packages. E.g. that requests requires idna, chardet and urllib3. This is read 
from upstream meatadata (.dist-info or egg-info directories/files). It has 
nothing to do with imports. See for example data in 
/usr/lib/python3.9/site-packages/requests-2.24.0-py3.9.egg-info/requires.txt.


/usr/lib/rpm/fileattrs/pythonname.attr

This file makes sure that packages called python3-requests provide 
python-requests and python3.9-requests.



There is no generator that parses Python imports (and never has been), sorry.

-- 
Miro Hrončok
--
Phone: [phone]
IRC: mhroncok