Failure to install ADT plugin to Eclipse - 'violates contract' error message

Question

Yesterday I had a problem about required items not being found when installing the ADT plugin in Eclipse. I got around that by opening up the download sites list and ticking the two bottom ones on the list, which for some reason were not selected. One of these addresses contained the word "mylyn". Now, when "fetchingjavax.xml_1.3.4. ........ /mylyn/drops......" (dots indicate other address parts), I had an error message:

An internal error occurred during: "Install download0". Comparison method violates its general contract!

which can be dismissed, but the installation appears to have stopped.

What to do next?

Answer 1

I had the same problem with Indigo running on a Java 7 VM and found out that eclipse has a problem to select the download mirror when using a Java 7 VM.

This Bug was fixed in eclipse milestone 3.7.1 (https://bugs.eclipse.org/bugs/show_bug.cgi?id=352089)

Here is my solution:

1. Add the new vmargs configuration property "-Djava.util.Arrays.useLegacyMergeSort=true" to eclipse.ini
2. Start and update eclipse to at least Indigo Service Release 1 (3.7.1).
3. Remove the configuration property listed on step one

Answer 2

I guess, you have JRE 7 installed and that's the problem. I tried the same thing, but always received this error message. On the eclipse-bugzilla, I found the advice, to downgrade JRE to version 6. So first uninstall JRE 7, than install JRE 6: Java 6u27 Download