We need to generalize 'package-with-python2'

We need to generalize 'package-with-python2'

[Mark H Weaver]

The 'python-dbus' package (called 'dbus-python' upsteam) uses the
'gnu-build-system', and like most other python libraries, there will be
two variants: 'python-dbus' and 'python2-dbus'.  Unfortunately,
'package-with-python2' only works on packages that use
'python-build-system'.  This is a problem.

It wouldn't be so bad to use 'inherit' to create 'python2-dbus' from
'python-dbus', but the more serious problem is that unless we generalize
'package-with-python2', it won't work properly on any package that uses
'python-dbus' as an input.

On the other hand, I realize that 'package-with-explicit-python'
intentionally avoids traversing into packages unless they use
'python-build-system', and that this is important for efficiency.

Any thoughts on how best to solve this?

      Mark

Re: We need to generalize 'package-with-python2'

[Eric Bavier]

On Tue, 03 Feb 2015 18:42:03 -0500
Mark H Weaver <mhw@netris.org> wrote:

> The 'python-dbus' package (called 'dbus-python' upsteam) uses the
> 'gnu-build-system', and like most other python libraries, there will
> be two variants: 'python-dbus' and 'python2-dbus'.  Unfortunately,
> 'package-with-python2' only works on packages that use
> 'python-build-system'.  This is a problem.
> 
> It wouldn't be so bad to use 'inherit' to create 'python2-dbus' from
> 'python-dbus', but the more serious problem is that unless we
> generalize 'package-with-python2', it won't work properly on any
> package that uses 'python-dbus' as an input.
> 
> On the other hand, I realize that 'package-with-explicit-python'
> intentionally avoids traversing into packages unless they use
> 'python-build-system', and that this is important for efficiency.
> 
> Any thoughts on how best to solve this?

Would it be enough to stop recursion when the bag inputs no longer
contain a python?

`~Eric

Re: We need to generalize 'package-with-python2'

[Ludovic Courtès]

Eric Bavier <bavier@member.fsf.org> skribis:

> On Tue, 03 Feb 2015 18:42:03 -0500
> Mark H Weaver <mhw@netris.org> wrote:
>
>> The 'python-dbus' package (called 'dbus-python' upsteam) uses the
>> 'gnu-build-system', and like most other python libraries, there will
>> be two variants: 'python-dbus' and 'python2-dbus'.  Unfortunately,
>> 'package-with-python2' only works on packages that use
>> 'python-build-system'.  This is a problem.
>> 
>> It wouldn't be so bad to use 'inherit' to create 'python2-dbus' from
>> 'python-dbus', but the more serious problem is that unless we
>> generalize 'package-with-python2', it won't work properly on any
>> package that uses 'python-dbus' as an input.
>> 
>> On the other hand, I realize that 'package-with-explicit-python'
>> intentionally avoids traversing into packages unless they use
>> 'python-build-system', and that this is important for efficiency.
>> 
>> Any thoughts on how best to solve this?
>
> Would it be enough to stop recursion when the bag inputs no longer
> contain a python?

Perhaps, but there’s also the problem that there’s no generic way to
communicate the Python to use (#:python in ‘python-build-system’) to
arbitrary build systems.

I’m not sure how to solve the problem Mark raises.

Perhaps ‘package-with-python2’ could be passed a set of mappings; we’d
give it the python-dbus -> python2-dbus mapping and it would just honor
it.  Thoughts?

Ludo’.