debian/changelog

+mat2 (0.8.0-2) experimental; urgency=medium
+
+  * d/control:
+    - Handle transition from mat to mat2: declare that mat2 breaks and
+      replaces mat << 0.8.0-2~, and ship a transitional package mat which
+      pulls in mat2. This upload targets experimental, to not interrupt the
+      ongoing migration process of 0.8.0-1.
+      For more details and discussion, see #910493.
+
+ -- Georg Faerber <georg@riseup.net>  Fri, 01 Mar 2019 15:33:38 +0000
+
 mat2 (0.8.0-1) unstable; urgency=medium
 
   * New upstream release.

debian/control

@@ -23,6 +23,8 @@ Vcs-Browser: https://salsa.debian.org/pkg-privacy-team/mat2
 Rules-Requires-Root: no
 
 Package: mat2
+Breaks: mat (<< 0.8.0-2~)
+Replaces: mat (<< 0.8.0-2~)
 Architecture: all
 Depends: gir1.2-gdkpixbuf-2.0,
          gir1.2-poppler-0.18,
@@ -72,3 +74,11 @@ Description: Metadata anonymisation toolkit v2
     - Torrent (.torrent)
     - Windows Media Video (.wmv)
     - ZIP (.zip)
+
+Package: mat
+Depends: mat2,
+         ${misc:Depends},
+Architecture: all
+Section: oldlibs
+Description: transitional package
+ This is a transitional package. It can safely be removed.