cmd/compile: internal compiler error: constant type mismatch

[OneOfOne]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

Go 1.8.3 / Go git

What operating system and processor architecture are you using (go env)?

Arch Linux 64

What did you do?

blah.go

package main

const ts int64 = 1483228800000000000 / time.Second

blah_test.go

package main
func Test(t *testing.T) {
	t.Logf("%v", ts)
}

What did you expect to see?

./id.go:7:2: cannot use 1483228800000000000 / time.Second (type time.Duration) as type int64 in const initializer

What did you see instead?

./blah.go:7:2: cannot use 1483228800000000000 / time.Second (type time.Duration) as type int64 in const initializer
./blah_test.go:16:39: internal compiler error: constant type mismatch int64(1) int64(0)

goroutine 1 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
        /usr/src/go/src/runtime/debug/stack.go:24 +0xa7
cmd/compile/internal/gc.Fatalf(0xb68f56, 0x24, 0xc4203b2858, 0x4, 0x4)
        /usr/src/go/src/cmd/compile/internal/gc/subr.go:181 +0x230
cmd/compile/internal/gc.evconst(0xc4204eb100)
        /usr/src/go/src/cmd/compile/internal/gc/const.go:941 +0x2a83
cmd/compile/internal/gc.typecheck1(0xc4204eb100, 0x2, 0x0)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:2215 +0x392
cmd/compile/internal/gc.typecheck(0xc4204eb100, 0x2, 0xc42030a200)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:201 +0x764
cmd/compile/internal/gc.typecheckslice(0xc4204ba780, 0x2, 0x2, 0x2)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:55 +0x54
cmd/compile/internal/gc.typecheck1(0xc4204eaf80, 0x12, 0xc4204eae80)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:1262 +0x455f
cmd/compile/internal/gc.typecheck(0xc4204eaf80, 0x12, 0xc4204eae80)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:201 +0x764
cmd/compile/internal/gc.typecheck1(0xc4204eaf00, 0x1, 0xc4204eac80)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:1260 +0x4abb
cmd/compile/internal/gc.typecheck(0xc4204eaf00, 0x1, 0xc4204eac80)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:201 +0x764
cmd/compile/internal/gc.typecheckslice(0xc4204ddaa0, 0x3, 0x4, 0x1)
        /usr/src/go/src/cmd/compile/internal/gc/typecheck.go:55 +0x54
cmd/compile/internal/gc.Main(0xb72f78)
        /usr/src/go/src/cmd/compile/internal/gc/main.go:480 +0x1fd0
main.main()
        /usr/src/go/src/cmd/compile/main.go:49 +0x95

[odeke-em]

@OneOfOne I can't seem to reproduce this error on 83fb9c8 i.e Go1.9

$ go version
go version devel +83fb9c8 Tue Jul 18 21:31:15 2017 +0000 darwin/amd64

at least as per https://github.com/odeke-em/bugs/tree/master/golang/21074.

I get back

$ go test -v
# _/Users/emmanuelodeke/Desktop/openSrc/bugs/golang/21074
./blah.go:5:7: cannot use 1483228800000000000 / time.Second (type time.Duration) as type int64 in const initializer
FAIL	_/Users/emmanuelodeke/Desktop/openSrc/bugs/golang/21074 [build failed]

which is the message that you want at least as per your report

Perhaps there is more to add to the bug report than has been reported? If so please help with the full repro, otherwise, please try on the Go1.9beta2 or tip, this seems fixed.

[OneOfOne]

That's odd, I can't reproduce it separately :-/
I'll reopen if I can make a better test case.