Compilation feature for alt-display by default

[stevenroose]

I find the default fmt::Display implementation not very useful and kinda always want the #-based alt display. For me, the power of the .context("...") pattern is that it adds context to the error, but if you don't use the alt-display, you're actually just replacing the error message, not adding anything.

Would this project accept a patch that adds an optional feature flag (alt-display or so) that makes that the default display method?

(I would personally go as far as arguing that the alt should be the default.)

[heroin-moose]

There is also a problem with alt-display: full chain. Printing the full chain often leads to this:

Nov 11 17:10:39 myhost foobard[1234]: Cannot open /run/foobard/socket: IO Error: Permission denied: Permission denied (error 22) 

Error reporting thus looks sloppy and unnecessary verbose. It would be nice to have an option to print only the first cause.