cmd/compile: can't use aliased type as underlying type in type parameter

[skdltmxn]

Go version

go version go1.23.0 darwin/arm64

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/gdpark/Library/Caches/go-build'
GOENV='/Users/gdpark/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/gdpark/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/gdpark/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/opt/homebrew/opt/go/libexec'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/homebrew/opt/go/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.23.0'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/gdpark/Library/Application Support/go/telemetry'
GCCGO='gccgo'
GOARM64='v8.0'
AR='ar'
CC='cc'
CXX='c++'
CGO_ENABLED='1'
GOMOD='/Users/gdpark/server/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/mz/71qhy0v14w188dvdrjyw499c0000gn/T/go-build1840556302=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

Starting from Go 1.23, I get 'invalid composite literal type T' error.
Please check the playground link which fails on Go 1.23.

https://go.dev/play/p/smVJSzGiGbn

I think I could not find any hint on this kind of change in release note, or was there?

What did you see happen?

Got 'invalid composite literal type T' error when building originally working codebase.

What did you expect to see?

Build should be successful.

[gabyhelp]

Related Issues and Documentation

• cmd/compile: internal compiler error when processing invalid recursive type #49276 (closed)
• cmd/go: breaking change in 1.23rc2 with version constraints in GOPATH mode #68658
• cmd/go: Go modules initialised by go1.21.1 cannot be built using go1.20.8 #63279 (closed)
• "internal compiler error: assertion failed" with generic code #53834 (closed)
• go build #52634 (closed)
• cmd/link: go test -c on darwin/arm64 produces invalid code signature in combination with cgo #63576 (closed)
• Test #67906 (closed)
• cmd/compile: internal compiler error with zero-size types #65808 (closed)
• go #64466 (closed)
• yaffaliu #56935 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[cuonglm]

@gopherbot please backport this issue to go1.23 release.

This is a bug in compiler type checker without any workaround.

[gopherbot]

Backport issue(s) opened: #68938 (for 1.23).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://go.dev/wiki/MinorReleases.

[gopherbot]

Change https://go.dev/cl/606635 mentions this issue: types2, go/types: fix missing Unalias call in coreType

[timothy-king]

Duplicate of #68903

[gopherbot]

Change https://go.dev/cl/606075 mentions this issue: go/types, types2: unalias tilde terms in underIs

[gopherbot]

Change https://go.dev/cl/607635 mentions this issue: [release-branch.go1.23] go/types, types2: unalias tilde terms in underIs