First of all, verify if you have a correct version of JAVA installed in your system
simple run the command:
java -version
if the version is java version "21.x.x" all good, go to compile, otherwise:
update-alternatives --config java
1 java-21-openjdk.x86_64 (/usr/lib/jvm/java-21-openjdk-21.0.2.0.13-1.fc39.x86_64/bin/java)
2 java-17-openjdk.x86_64 (/usr/lib/jvm/java-17-openjdk-17.0.9.0.9-3.fc39.x86_64/bin/java)
*+ 3 /usr/lib/jvm/jdk-21-oracle-x64/bin/java
if you version of java selected is 21, go to configure ant, otherwise, select the correct version OR if not found a version 21, with ant, install it with
Ubuntu / Debian / Others based in Debian/Ubuntusudo apt instal java-21-opensdk ant
Arch Linux / Manjaro / Others based on Archsudo pacman -S java-21-opendsk ant
Red Hat / Fedora / Others based in Red Hatsudo dnf install java-21-opensdk ant
COMPILE!
All good? maybe... try it!
Go to the directory of source and type
ant
After compiling...
../build
That's all, problems? well, is a simple tutorial, not complex but works, post any doubts you have... good luck