go1: internal compiler error: in do_lower, at go/gofrontend/statements.cc:3791
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.archlinux.org/> for instructions.

£ go version
go version go1.10.3 gccgo (GCC) 8.2.1 20180831 linux/amd64

func (c *connection) handleMessage(msg *message) (err error) {
for k,v := range msg {
switch k {
case "request_content":
r := &make(message)
(*r)["content_html"] = generateHtmlRedirect("https://xkcd.net")
c.send <- r
}
}
return
}

After either one of these changes, regular compile errors appear:
- r := &make(message)
+ r := make(message)
or
- (*r)["content_html"] = generateHtmlRedirect("https://xkcd.net")
+ r["content_html"] = generateHtmlRedirect("https://xkcd.net")

Apply both, and the internal error re-appears.