I tried extending the example by importing one of the dependencies with something like

import org.acra.annotation.*;

in the main activity. While this works fine in Eclipse, running ant debug install on the command line fails to compile:

-compile:
    [javac] Compiling 3 source files to /mnt/home/pascal/Downloads/src/IvyAndroidExample/bin/classes
    [javac] /mnt/home/pascal/Downloads/src/IvyAndroidExample/src/com/example/IvyAndroidExampleActivity.java:5: package org.acra.annotation does not exist
    [javac] import org.acra.annotation.*;
    [javac] ^
    [javac] 1 error

Do you have any idea how to solve this? Do you need to add something to the build.xml to adjust the class path the Android tool chain is using?