https://bugs.winehq.org/show_bug.cgi?id=35522
--- Comment #9 from Dmitry Timoshkov dmitry@baikal.ru --- (In reply to François Gouget from comment #8)
That's because you left the "Test Executable" field empty, which is not a valid test executable name.
It's not required when submitting a .diff in multiple steps, I don't see why this should differ in a single page UI.
Also notice that patches may modify more than one test module in which case the TestBot has no way of knowing which one you intended to test (jobs submitted through the website are still limited to running a single test unit). But in the simple case it could indeed provide a default value if that field is left blank.
Once again, this isn't different from a multi-page UI.
Notice however that for the "Command line arguments" field it cannot know if you really intended to pass no parameter to the test executable or whether a default value should be provided (and there too the value to use could be ambiguous).
A way to lift this ambiguity would be to have a box that must be checked to provide custom command line arguments. But that would really only be useful for the Single Page mode since in the normal case a default is provided.
Again, I don't see why you are trying to make single page UI to require anything more that multi-page UI does not.