What did you see happen?

root@acmcoder:/home/acmcoder/cgo# go version
go version go1.22.0 linux/amd64
root@acmcoder:/home/acmcoder/cgo# go run main.go
STAGE_PARENT
STAGE_CHILD
STAGE_INIT
This from nsexec

What did you expect to see?

root@acmcoder:/home/acmcoder/cgo# go version
go version go1.21.1 linux/amd64
root@acmcoder:/home/acmcoder/cgo# go run main.go
STAGE_PARENT
STAGE_CHILD
STAGE_INIT
This from nsexec
From main!

Difference

The last line From main! is gone in go1.22.0.