I had the same problem on Windows. Changed the way of passing parameters to -D “key=value” and it worked. In your case, it would be:
./gradlew sonarqube -D "sonar.projectKey=summer_project" -D "sonar.host.
url=http://localhost:8080" -D "sonar.login=sqp_7aaad155dded0949a59858310d1fdaba2690ef1d"