Setting environment variables from Gradle - ant

Question

I need to execute from Gradle an Ant script which relies on environment variables.
Ant uses <property environment="env"/> for it.
I tried to do env.foo="bar" in Gradle, but it throws a Groovy exception.
What is the proper way to pass environment variables from Gradle to Ant?

Answer 1

From the gradle 2.0 docs, i see something like this is possible
test {
environment "LD_LIBRARY_PATH", "lib"
}
Or in this case could use this
systemProperty "java.library.path", "lib"

Answer 2

It is impossible to set environment variables from Gradle or JVM in general, but it is possible to trick Ant like this:
ant.project.properties['env.foo'] = 'bar'

Answer 3

Accepted solution from #Sergey:
ant.project.properties['env.foo'] = 'bar'
Does not work for me on gradle 2.9 and ant 1.9.7.
That did not thrown any error, but do nothing. Indeed if you are look at code it implemented as:
public Hashtable<String, Object> getProperties() {
return PropertyHelper.getPropertyHelper(this).getProperties();
}
where org.apache.tools.ant.PropertyHelper#getProperties is:
public Hashtable<String, Object> getProperties() {
//avoid concurrent modification:
synchronized (properties) {
return new Hashtable<String, Object>(properties);
}
}
So it make explicit copy and it can't work.
The way do it correctly in gradle file:
ant.project.setProperty('env.foo', 'bar')
Documentation mention few other ways (note, without project):
ant.buildDir = buildDir
ant.properties.buildDir = buildDir
ant.properties['buildDir'] = buildDir
ant.property(name: 'buildDir', location: buildDir)