by malkia:

Before filing a bug, please check whether it has been fixed since
the latest release: run "hg pull -u" and retry what you did to
reproduce the problem.  Thanks.

What steps will reproduce the problem?
1. Compile the provided sample
2. Notice the compiler reports a fatal error with some internal messages.

What is the expected output? What do you see instead?
- Correct output woudl be no output, which means the compilation succeeded.
- Instead, I'm getting this:
defn [1002aeb28] 
.   AS2MAPR l(9) x(-1000000000) tc(1) 
.   AS2MAPR-list 
.   .   NAME-shortarch G0 u(1) a(1) l(9) class(1) tc(1) string 
.   .   NAME-shortarchOK G0 u(1) a(1) l(9) class(1) tc(1) bool 
.   AS2MAPR-rlist 
.   .   INDEXMAP l(9) x(-1000000000) tc(1) string 
.   .   .   NAME-archmap G0 u(1) a(1) l(6) class(1) tc(1) map[string] 
string 
.   .   .   NAME-longarch G0 u(1) a(1) l(7) class(1) tc(1) string 
map-bug.go:15: fatal error: init1: bad defn 


What is your $GOOS?  $GOARCH?
GOOS=darwin
GOARCH=amd64

Which revision are you using?  (hg identify)
4333:6892511bb0df 

Please provide any additional information below.
I'm providing you with a source file that reproduces the problem.

// map-bug.go

package main 

import ( "fmt"; "os") 

var ( 
        archmap = map[string]string{"Xamd64":"6", "x86":"8", "arm":"5"}; 
        longarch = os.Getenv("GOARCH"); 
        curdir, curdirOK = os.Getwd();               // Here curdirOK is fine 
        shortarch, shortarchOK = archmap[longarch];  // Here shortarchOK troubles the compiler. 
) 

func main() 
{ 
        fmt.Println("shortarch=" + shortarch); 
}