in maven-wrapper/src/main/java/org/apache/maven/wrapper/PathAssembler.java [79:87]
private Path getBaseDir(String base) {
if (MAVEN_USER_HOME_STRING.equals(base)) {
return mavenUserHome;
} else if (PROJECT_STRING.equals(base)) {
return Paths.get(System.getProperty("user.dir"));
} else {
throw new RuntimeException("Base: " + base + " is unknown");
}
}