I have a custom definition for my LXD cloud, which has an endpoint in the form IP:port.
Any such configuration will cause a panic at bootstrap like this:
goroutine 1 [running]:
net/url.(*URL).Hostname(...)
/usr/local/go/src/net/url/url.go:1144
github.com/juju/juju/provider/lxd.(*environ).DetectHardware(0xc00080f400)
/home/joseph/go/src/github.com/juju/juju/provider/lxd/environ.go:486 +0xf3
github.com/juju/juju/environs/bootstrap.bootstrapIAAS({_, _}, {_, _}, {_, _}, {{0x0, 0x0, 0x0, 0x0, ...}, ...}, ...)
/home/joseph/go/src/github.com/juju/juju/environs/bootstrap/bootstrap.go:352 +0x3bf
github.com/juju/juju/environs/bootstrap.Bootstrap({_, _}, {_, _}, {_, _}, {{0x0, 0x0, 0x0, 0x0, ...}, ...})
/home/joseph/go/src/github.com/juju/juju/environs/bootstrap/bootstrap.go:741 +0x409
github.com/juju/juju/cmd/juju/commands.bootstrapFuncs.Bootstrap(...)
/home/joseph/go/src/github.com/juju/juju/cmd/juju/commands/bootstrap.go:517
github.com/juju/juju/cmd/juju/commands.(*bootstrapCommand).Run(0xc000621400, 0xc00004e4e0)
/home/joseph/go/src/github.com/juju/juju/cmd/juju/commands/bootstrap.go:1061 +0x2d49
github.com/juju/juju/cmd/modelcmd.(*modelCommandWrapper).Run(0xc000ce9350, 0xc000e55b30?)
/home/joseph/go/src/github.com/juju/juju/cmd/modelcmd/modelcommand.go:663 +0x123
github.com/juju/juju/cmd/modelcmd.(*baseCommandWrapper).Run(0xc0002f8380, 0x200000006?)
/home/joseph/go/src/github.com/juju/juju/cmd/modelcmd/base.go:552 +0xaf
github.com/juju/cmd/v3.(*SuperCommand).Run(0xc0002d6640, 0xc00004e4e0)
/home/joseph/go/src/github.com/juju/juju/vendor/github.com/juju/cmd/v3/supercommand.go:534 +0x378
github.com/juju/cmd/v3.Main({0x4eb12d8, 0xc0002d6640}, 0xc00004e4e0, {0xc0004ba680, 0x4, 0x4})
/home/joseph/go/src/github.com/juju/juju/vendor/github.com/juju/cmd/v3/cmd.go:419 +0x25d
github.com/juju/juju/cmd/juju/commands.jujuMain.Run({0xc0000ee140?}, {0xc0000740a0, 0x5, 0x5})
/home/joseph/go/src/github.com/juju/juju/cmd/juju/commands/main.go:202 +0x80f
github.com/juju/juju/cmd/juju/commands.Main(...)
/home/joseph/go/src/github.com/juju/juju/cmd/juju/commands/main.go:125
main.main()
/home/joseph/go/src/github.com/juju/juju/cmd/juju/main.go:27 +0x72
PR https:/ /github. com/juju/ juju/pull/ 15350