cmd/compile: cannot handle alias type declaration

[ZenLiuCN]

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

go version go1.14.2 windows/amd64.

Does this issue reproduce with the latest release?

haven check yet.

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

go env Output

set GO111MODULE=on
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\Administrator\AppData\Local\go-build
set GOENV=C:\Users\Administrator\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=D:\gosrc\src
set GOPRIVATE=
set GOPROXY=http://goproxy.cn
set GOROOT=D:\golang
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=D:\golang\pkg\tool\windows_amd64
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=D:\src\mrp\go.mod
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\ADMINI~1\AppData\Local\Temp\go-build890466410=/tmp/go-build -gno-record-gcc-switches

What did you do?

1. with go mod enabled
2. with those file in same package

// some_file.go
package mrp
type Runtime interface {
	RevertThen(i int, fragment Fragment)
}
type (
	Fragment             = func(Runtime) bool
)
//Rutime.go
package mrp

type runtime struct {
	stack     []interface{}
	revert    int
	revertPtr int
	parameter map[string]interface{}
}

func (r runtime) RevertThen(i int, fragment Fragment) {
	panic("implement me")
}

What did you see instead?

.\some_file.go:5:2: internal compiler error: cannot handle alias type declaration (issue #25838): Fragment

this will and only will happend under :

1. implment file is name within upper-case;
2. interface is defined in separate file, and this file contains no upper-case ;

[mdempsky]

Thanks for providing more details. I think this is #25838 actually. Here's a standalone file that produces the same failure: https://play.golang.org/p/0Cxmszie2hW

Case is relevant because it probably affects how cmd/go sorts file names, which affects the order that cmd/compile processes declarations. I think if you put the interface after the implementation in your file, it'll still reproduce too.

Closing as a duplicate.