mod=example.com/basic/v2
version=v2.1.0
base=v2.0.1
proxyVersions=example.com/basic/v2@v2.0.1
-- want --
# example.com/basic/v2/a
## compatible changes
A2: added

# example.com/basic/v2/b
## compatible changes
package added

# summary
Suggested version: v2.1.0