// so omitting @v will drop existing replacements for specific versions.
//
// The -dropreplace=old[@v] flag drops a replacement of the given
// module path and version pair. If the @v is omitted, a replacement without
// a version on the left side is dropped.
//
// The -retract=version and -dropretract=version flags add and drop a

	p.SysoFiles = pp.SysoFiles
	if cfg.BuildMSan {
		// There's no way for .syso files to be built both with and without
		// support for memory sanitizer. Assume they are built without,
		// and drop them.
		p.SysoFiles = nil
	}
	p.CgoCFLAGS = pp.CgoCFLAGS
	p.CgoCPPFLAGS = pp.CgoCPPFLAGS
	p.CgoCXXFLAGS = pp.CgoCXXFLAGS
	p.CgoFFLAGS = pp.CgoFFLAGS
	p.CgoLDFLAGS = pp.CgoLDFLAGS

		}

		if a == root {
			close(b.readySema)
		}
	}

	var wg sync.WaitGroup

	// Kick off goroutines according to parallelism.
	// If we are using the -n flag (just printing commands)
	// drop the parallelism to 1, both to make the output
	// deterministic and because there is no real work anyway.
	par := cfg.BuildP
	if cfg.BuildN {
		par = 1
	}
	for i := 0; i < par; i++ {
		wg.Add(1)