+3) Update the debian/libnotmuch1.symbols file
+
+ If the library version changed at all (step 2) it probably
+ means that symbols have changed/been added, in which case the
+ debian symbols file also needs to be updated:
+
+ dpkg-buildpackage -uc -us
+ dpkg-gensymbols -plibnotmuch1 | patch -p0
+
+ Carefully review the changes to debian/libnotmuch1.symbols to
+ make sure there are no unexpected changes.
+
+ Commit this change, if any.
+
+4) Upgrade the version in the file "version"