Copying junit to system dir for Time 27 when there is a system-wide Ant installation

[Tbabm]

This issue seems to be the same as #254 .

Environment:

• OS: ubuntu 20.04
• defect4j version: master, 397075d427d44d153fa5436f4b82d58f0afea712

When there is a system-wide Ant installation, if I run gen_tests.pl for Time 27b and then execute run_bug_detection.pl on the generated test suites, I will encounter the following build failure:

Attempt to copy /path/defects4j/framework/projects/lib/junit-4.11.jar to /usr/share/ant/lib/junit-4.11.jar using NIO Channels failed due to '/usr/share/ant/lib/junit-4.11.jar'.  Falling back to streams.

If I uninstall the system-wide Ant, everything becomes ok. Is this the expected behavior or a bug?

Steps to reproduce:

# install defects4j
gen_tests.pl -g evosuite -p Time -v 27b -n 1 -o . -b 180
run_bug_detection.pl -p Time -d Time/evosuite/1 -o .
# everything is ok

sudo apt install ant
gen_tests.pl -g evosuite -p Time -v 27b -n 1 -o . -b 180
run_bug_detection.pl -p Time -d Time/evosuite/1 -o .
# encounter the build failure

sudo apt remove ant
gen_tests.pl -g evosuite -p Time -v 27b -n 1 -o . -b 180
run_bug_detection.pl -p Time -d Time/evosuite/1 -o .
# everything becomes ok again