One way to work around this until the package gets fixed in xenial is to escape the % sign in the JAVA_OPTS string:
JAVA_OPTS="${JAVA_OPTS} -Xloggc:/var/log/tomcat7/gc-\%t.log"
This has been tested and seems to make both the postinst script work, as well as make the JVM include the timestamp in the GC log file at runtime.
One way to work around this until the package gets fixed in xenial is to escape the % sign in the JAVA_OPTS string:
JAVA_OPTS= "${JAVA_ OPTS} -Xloggc: /var/log/ tomcat7/ gc-\%t. log"
This has been tested and seems to make both the postinst script work, as well as make the JVM include the timestamp in the GC log file at runtime.