On Jun 25, 2007, at 09:46, Taylor R Campbell wrote:
Actually, it occurs to me that it's not really necessary to declare a dependency -- that it would suffice for the variant to have a command that checks for the existence of an executable by some name, and to refuse to continue if this command fails.
I haven't really followed why all this complexity with the multiple scheme ports is required -- I realize you tried to spell it out in your first email but it was a bit much for me at the moment. But assuming it really is required, then yes, this is the method that occurred to me as well: just test for the file's existence in, say, the pre-fetch phase, and fail if not found. I don't, however, know the portfile syntax for checking for a file's existence.
There was some recent discussion about a `ui_fatal' command by which to fail, although I understand that it was simply a proposal not yet implemented. Does this sound plausible, however?
Not really needed, though, either. Just do ui_error "the message" followed by exit 1. And, again, do this in the pre-fetch phase.