A make variable like JTREG="JAVA_OPTIONS=-Djava.security.debug=all;MAX_OUTPUT=1000000" could end up losing the quotes and thus the shell will split at ; in reinvocations of make. For the JTREG variable specifically, this is a regression since JDK-8348586, that moved JTREG from INIT_CONTROL_VARIABLES to MAKE_CONTROL_VARIABLES, which were not properly treated.