Multiple DEBs provide virtual package, which is listed as Depends

Paul Grinberg

12/9/22, 6:31 PM

I have my own APT repo which houses custom DEBs created/packaged by me. In this repo are a set of DEB packages which have the following in their control file

Package: my-foo-<type>
Architecture: any
Section: admin
Provides: my-foo
Conflicts: my-foo

where <type> is one of several types (e.g. abc, def, etc). In other words, I have multiple actual packages which provide the same virtual my-foo package. As expected, if I try to run apt install my-foo, I am presented with the expected prompt

Package my-foo is a virtual package provided by:
  my-foo-abc 0.3.0-1
  my-foo-def 0.4.3-1
You should explicitly select one to install.

I also have another package in the same repo which has Depends: my-foo in its control file. I expected that when I try to install this package without having explicitly specified which my-foo virtual flavor to use, I should likewise be prompted for a selection. However, that's not what I get - apt seemingly selects the first package which satisfied the virtual package name.

Is there a way to force the desired behavior?

1 + 3

dependencies

debian

deb

Pablo Bianchi

12/13/22, 8:44 PM

Does [this](https://askubuntu.com/a/739065/349837) answer help you?

Paul Grinberg

12/15/22, 1:37 PM

@PabloBianchi - Thanks for the link. The answer clarifies the behavior, although it doesn't help me achieve what i was desiring

James S.

12/19/22, 7:12 PM

Your desired behavior is counter to the spec. From the spec, at [Debian Packaging Policy](https://www.debian.org/doc/debian-policy/ch-relationships.html#virtual-packages-provides) To specify which of a set of real packages should be the default to satisfy a particular dependency on a virtual package, list the real package as an alternative before the virtual one.

Score:1

Ubuntu

Robie Basak

12/20/22, 12:09 PM

I expected that when I try to install this package without having explicitly specified which my-foo virtual flavor to use, I should likewise be prompted for a selection.

apt provides no such mechanism. I'm not sure what more can be said about this. You're expecting something that does not exist. There is no code in apt to provide such a prompt.

As @James S. pointed out, it will prefer the first non-virtual alternative if alternatives are given and all dependencies would be met by its selection. Otherwise, the dependency resolver will find a solution without prompting.

0 + 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Multiple DEBs provide virtual package, which is listed as Depends

TH: DEB หลายรายการจัดเตรียมแพ็คเกจเสมือน ซึ่งแสดงรายการเป็น ขึ้นอยู่กับ

RO: Mai multe DEB-uri oferă pachet virtual, care este listat ca Depende

RU: Несколько DEB предоставляют виртуальный пакет, который указан как Зависит.

VI: Nhiều DEB cung cấp gói ảo, được liệt kê là Phụ thuộc

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