Short urls for error messages?

[jpjp]

How about adding short urls to error messages to find out an explanation? It might cut down on duplicate questions on the discourse board.

[calmh]

Good idea.

[calmh]

I started looking into doing this, but it turns out to be tricky. With few exceptions, Syncthing just reports a random error generated somewhere else, i.e.

jb@jborg-mbp:~/src/github.com/syncthing/syncthing (master) $ git grep 'l.Warn'
beacon/beacon.go:                       l.Warnln("Beacon read:", err)
beacon/beacon.go:                       l.Warnln("Beacon: interface addresses:", err)
cmd/syncthing/gui.go:           l.Warnln(err)
cmd/syncthing/gui.go:                           l.Warnln(err)
cmd/syncthing/gui.go:           l.Warnln(err)
cmd/syncthing/gui.go:                   l.Warnln(err)
cmd/syncthing/gui_solaris.go:                   l.Warnln(err)
cmd/syncthing/main.go:                  l.Warnln("Key exists; will not overwrite.")
cmd/syncthing/main.go:          l.Warnln("Invalid lock port %q: %v", lockPortStr, err)
...etc etc

where err is an error description received from the operating system along the lines of "connection refused", "permission denied", "no space left on device" or the classic "EOF". To be able to categorize these usefully we'd have to parse the returned error string and look for patterns, which are obviously platform specific (i.e. entirely different on Windows than Linux etc). As such, I don't see how to implement this.

[Nutomic]

Does Go not use error classes, like Java has Exception classes (with inheritance and all)?

If not, you might want to create your own classes wherever you throw the error (or see it for the first time if it's coming somewhere external), and then check the error class later?

[calmh]

No