code: File findRepoPath(final String repoAlias) {
          if ("user".equals(repoAlias)) {
              return new File(System.getProperty("user.home") 
                  + CeylonUtil.PATH_SEPARATOR 
                  + ".ceylon/repo");
          } else if ("cache".equals(repoAlias)) {
              return new File(System.getProperty("user.home") 
                  + CeylonUtil.PATH_SEPARATOR 
                  + ".ceylon/cache");            
          } else if ("system".equals(repoAlias)) {
              throw new IllegalArgumentException("Ceylon Repository 'system' should not be written to");
          } else if ("remote".equals(repoAlias)) {
              throw new IllegalArgumentException("Ceylon Repository 'remote' should use the ceylon:deploy Maven goal");
          } else if ("local".equals(repoAlias)) {
              return new File(project.getBasedir(), "modules");
          } else {
              throw new IllegalArgumentException(
                  "Property ceylonRepository must one of 'user', 'cache' or 'local'. Defaults to 'user'");
          }  
      }
docs: Find the Ceylon repository path from the alias.
  
  @param repoAlias The Ceylon repository alias
  @return File The file representing the path to the repo