Fixed some bugs that made the solver incorrect.

1 job for master in 18 seconds (queued for 4 seconds)
Name Stage Failure
mybuild Build There is an unknown failure, please try again
	at org.eclipse.aether.connector.basic.BasicRepositoryConnector$GetTaskRunner.runTask(
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$
... 32 more
6724 [ERROR]
6724 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
6724 [ERROR]
6724 [ERROR] For more information about the errors and possible solutions, please read the following articles:
6724 [ERROR] [Help 1]
ERROR: Job failed: exit code 1