Comment 5 for bug 1789047

@Jeff, this is an internal requirement so the assertion is doing it's job. The schematic and board file plugins expect absolute paths by design. In the past we allowed relative paths which caused all kinds of issues because devs were changing the cwd when saving files to other paths and forgetting to change it back to the project path so we made absolute paths mandatory internally. This is a requirement for developers not users. Users are free to use relative paths, it is the developers responsibility to resolve relative paths before manipulating files. Since this has only been reported in the dev branch and not the stable 5 branch, I suspect code that resolved relative paths to absolute paths accidentally got removed. Please do no remove the assertion.