x/playground: cgo builds fail (e.g., importing "net" package) because "gcc" executable not found in $PATH

[bradfitz]

The playground is currently broken. e.g. https://play.golang.org/p/NbF8QOGEaYB

package main

import (
	"fmt"
	"net"
)

func main() {
	fmt.Println(net.ParseIP("1.2.3.4"))
}

Results in:

# net
cgo: exec gcc: exec: "gcc": executable file not found in $PATH

Go build failed.

/cc @dmitshur

[dmitshur]

We've recently changed PATH as part of fixing for Go 1.16, maybe this is relevant.

CC @toothrot.

[toothrot]

I'm not sure if it's a PATH issue as much as it could be an issue with how we're building Go now. I don't think gcc has been present in the final container for a while. I'll take a look.

[toothrot]

We've determined that net is being marked stale now, and that this is broken as of golang.org/cl/295649 (golang/playground@9028cb5), but have yet to determine why.

[gopherbot]

Change https://golang.org/cl/297636 mentions this issue: all: set CGO_ENABLED=0 when building snippets