Golang unique: panic when calling unique.Make with string casted as any

Go version

go version go1.23.0 linux/amd64

Output of go env in your module/workspace:

Go playground

What did you do?

Casting a string to any and passing it to unique.Make seems to cause issues.

package main

import "unique"

func main() {
    unique.Make(any(""))
}

Example crash 1 unexpected fault address 0x912c08: https://go.dev/play/p/vZWwiXU6YXL Example crash 2 panic: interface conversion: interface {} is *unique.uniqueMap[string], not *unique.uniqueMap[interface {}]: https://go.dev/play/p/U8JvXsqXpJQ

What did you see happen?

For it not to crash

What did you expect to see?

I expected to see nothing and the program not to crash

Comment From: gabyhelp

Related Issues and Documentation

• go/types, types2: go generic assert compile escape #52228 (closed)
• cmd/compile/internal/types2: panic when type function selector is not instantiated #48048 (closed)
• go/types: crash in assignment between "unexported" named interface types #5512 (closed)
• runtime: SIGBUS in initItab (write to readonly ITab.Fun) on unchecked type assertion with generics #65962 (closed)
• go/types, govet: panics when encountering (string constant) + string(rune constant) #4982 (closed)

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Comment From: ianlancetaylor

CC @mknyszek

Comment From: mknyszek

Looking into it.

Comment From: mknyszek

I see the general problem -- it's a classic reflection mistake when trying to get the type of a value (via TypeOf). This package doesn't use reflection directly, but does something reflect-like to extract the type.

Easy fix, apologies for the breakage.

Comment From: gopherbot

Change https://go.dev/cl/607355 mentions this issue: unique: use TypeFor instead of TypeOf to get type in Make

Comment From: mknyszek

@gopherbot Please open a backport issue for Go 1.23.

This problem accidentally limits what types the unique package can work with, and results in panics. Also, the fix is very simple and low risk.

Comment From: gopherbot

Backport issue(s) opened: #68992 (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.

Comment From: ALX99

Appreciate the insanely quick response. Thank you for your contributions to Go!

Comment From: gopherbot

Change https://go.dev/cl/607435 mentions this issue: [release-branch.go1.23] unique: use TypeFor instead of TypeOf to get type in Make