Update build/builder.go

Co-authored-by: Keegan Carruthers-Smith <[email protected]>

build/builder.go

@@ -184,7 +184,7 @@ func (o *Options) Flags(fs *flag.FlagSet) {
 	fs.StringVar(&o.IndexDir, "index", x.IndexDir, "directory for search indices")
 	fs.BoolVar(&o.CTagsMustSucceed, "require_ctags", x.CTagsMustSucceed, "If set, ctags calls must succeed.")
 	fs.Var(largeFilesFlag{o}, "large_file", "A glob pattern where matching files are to be index regardless of their size. You can add multiple patterns by setting this more than once.")
-	fs.StringVar(&o.ShardPrefix, "shard_prefix", x.ShardPrefix, "the prefix of the shard. If empty, the repository name is used.")
+	fs.StringVar(&o.ShardPrefix, "shard_prefix", x.ShardPrefix, "the prefix of the shard. Defaults to repository name")
 
 	// Sourcegraph specific
 	fs.BoolVar(&o.DisableCTags, "disable_ctags", x.DisableCTags, "If set, ctags will not be called.")