I'm using your package to develop syntax highlighting, and when i convert yaml to plist using build system of the package it puts that message to Sublime console
[PackageDev] File conversion unsuccessful. (yaml -> plist)
but conversion was success. Then I find out in the package source following line of code which can produce that message I think.
https://github.com/SublimeText/AAAPackageDev/blob/b1e61d9c404d101c86aef0744d5c3b7a773c684a/file_conversion.py#L242-L243
So, is it feature of the package to print unsuccess message when convertion was success?