mod=example.com/basic/v2
version=v2.1.2
base=v2.1.1-pre
proxyVersions=example.com/basic/v2@v2.1.1-pre
-- want --
# example.com/basic/v2/a
## incompatible changes
A2: removed

# example.com/basic/v2/b
## incompatible changes
package removed

# summary
Suggested version: v2.1.1