pkgSpecials = make(map[string]PkgSpecial)
		set := func(elt string, f func(*PkgSpecial)) {
			s := pkgSpecials[elt]
			f(&s)
			pkgSpecials[elt] = s
		}
		for _, pkg := range runtimePkgs {
			set(pkg, func(ps *PkgSpecial) { ps.Runtime = true; ps.NoInstrument = true })
		}
		for _, pkg := range extraNoInstrumentPkgs {
			if pkg[0] == '-' {
				set(pkg[1:], func(ps *PkgSpecial) { ps.NoInstrument = false })