One reasonable setting for this variable is to use the commit timestamp from the
tip of the tree being built; this is what the Kubernetes CI system uses. For
example, you could use the following one-liner:

```bash
SOURCE_DATE_EPOCH=$(git show -s --format=format:%ct HEAD)

// (instead of invoking GNU binutils).
// A file represents a single executable being analyzed.
type file struct {
	name   string
	offset uint64
	sym    []objfile.Sym
	file   *objfile.File
	pcln   objfile.Liner

	triedDwarf bool
	dwarf      *dwarf.Data
}

func (f *file) Name() string {
	return f.name
}

func (f *file) ObjAddr(addr uint64) (uint64, error) {
	return addr - f.offset, nil
}