Install libsolv from Buster to allow sid builds

Author: athos-ribeiro

salt/files/sources.list

@@ -1,5 +1,6 @@
 deb http://httpredir.debian.org/debian stretch main
 deb http://httpredir.debian.org/debian stretch-backports main
+deb http://httpredir.debian.org/debian buster main
 deb-src http://httpredir.debian.org/debian sid main
 deb-src http://httpredir.debian.org/debian buster main
 deb-src http://httpredir.debian.org/debian jessie main

salt/obs.sls

@@ -37,6 +37,14 @@ install_obs_build_from_backports:
       - obs-build
     - fromrepo: stretch-backports
 
+install_libsolv_from_testing:
+  pkg.latest:
+    - pkgs:
+      - libsolv0
+      - libsolv-perl
+      - libsolvext0
+    - fromrepo: buster
+
 /usr/share/obs/api/Gemfile:
   file.managed:
     - source: salt://files/Gemfile