Old issue.I thought it was fixed. Basically the lib/ folder files are loaded in reverse alphabetical order, not dependency order. So this may make imports of sibling classes fail if the filenames don't match the dependency order.

The workaround is to make sure the file you are importing is later in sort order than your name. Note that groovy does not insist that class names correspond to file names.

One way to fix this in code is to retry loading. If you have N source files in lib/ you can load them and track the ones that failed. then reload them and track again. if you get no progress, then you bail out of the loop. You would have to execute the loop at most N times.