diff -r 149b0703265f libgo/syscalls/syscall_linux_386.go
--- a/libgo/syscalls/syscall_linux_386.go	Sun Jun 13 22:23:02 2010 -0700
+++ b/libgo/syscalls/syscall_linux_386.go	Sun Jun 13 22:25:02 2010 -0700
@@ -6,6 +6,8 @@
 
 package syscall
 
+const ARCH = "386"
+
 func (r *PtraceRegs) PC() uint64 {
 	return uint64(uint32(r.Eip));
 }
diff -r 149b0703265f libgo/syscalls/syscall_linux_amd64.go
--- a/libgo/syscalls/syscall_linux_amd64.go	Sun Jun 13 22:23:02 2010 -0700
+++ b/libgo/syscalls/syscall_linux_amd64.go	Sun Jun 13 22:25:02 2010 -0700
@@ -6,6 +6,8 @@
 
 package syscall
 
+const ARCH = "amd64"
+
 func (r *PtraceRegs) PC() uint64 {
 	return r.Rip;
 }