Conflict between libtorch3-dev and lima packages

[kleag]

Describe the bug
One cannot install the libtorch3-dev package together with the lima package due to the fact they install the same /usr/lib/libtorch.so file.

To Reproduce
Steps to reproduce the behavior:

1. Install lima package from https://github.com/aymara/lima/releases
2. Install libtorch3-dev package
3. Fail with:

$ sudo apt install libtorch3-dev
Lecture des listes de paquets... Fait
Construction de l'arbre des dépendances       
Lecture des informations d'état... Fait
Starting pkgProblemResolver with broken count: 0
Starting 2 pkgProblemResolver with broken count: 0
Done
Les NOUVEAUX paquets suivants seront installés :
  libtorch3-dev
0 mis à jour, 1 nouvellement installés, 0 à enlever et 0 non mis à jour.
Il est nécessaire de prendre 834 ko dans les archives.
Après cette opération, 2 678 ko d'espace disque supplémentaires seront utilisés.
Réception de :1 http://fr.archive.ubuntu.com/ubuntu focal/universe amd64 libtorch3-dev amd64 3.1-2.2build1 [834 kB]
834 ko réceptionnés en 10s (80,9 ko/s)  
Sélection du paquet libtorch3-dev précédemment désélectionné.
(Lecture de la base de données... 832303 fichiers et répertoires déjà installés.)
Préparation du dépaquetage de .../libtorch3-dev_3.1-2.2build1_amd64.deb ...
Dépaquetage de libtorch3-dev (3.1-2.2build1) ...
dpkg: erreur de traitement de l'archive /var/cache/apt/archives/libtorch3-dev_3.1-2.2build1_amd64.deb (--unpack) :
 tentative de remplacement de « /usr/lib/libtorch.so », qui appartient aussi au paquet lima-tf 3.0.0+202110131537540200-a2559ec4
Des erreurs ont été rencontrées pendant l'exécution :
 /var/cache/apt/archives/libtorch3-dev_3.1-2.2build1_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

Expected behavior
Both packages should install without conflict

Desktop (please complete the following information):

• OS: Ubuntu 20.04

[victorbocharov]

1. I confirm the problem.
2. It's different in 20.04 and in 21.04 (and later versions):

• in 20.04 libtorch3-dev is something different from C++ interface of PyTorch
• in 21.04 and later libtorch-dev is actually the C++ interface of PyTorch - the one LIMA depends on

For 21.04 the solution is to start using the version of libtorch that comes from the distribution (but this doesn't work now). For 20.04 it's not so clear for me now.

[kleag]

For 21.04 the solution is to start using the version of libtorch that comes from the distribution (but this doesn't work now).
What doesn't work now? And why?

For 20.04 it's not so clear for me now.
Could we rename the lib we install from extern/… into something like libtorch-lima.so and link with this one? It is again a renaming of a lima dependency for its sole usage but this time it is only an interim solution.

[kleag]

Hi @victorbocharov , any change on this issue?