UNIX symbols from 20200831 wasn't working (#169)

When build for GOOS=darwin

go.mod

@@ -43,15 +43,14 @@ require (
 	golang.org/x/mod v0.3.0
 	golang.org/x/net v0.0.0-20200822124328-c89045814202 // indirect
 	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208 // indirect
-	golang.org/x/sys v0.0.0-20200831180312-196b9ba8737a // indirect
-	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
 	google.golang.org/genproto v0.0.0-20200831141814-d751682dd103 // indirect
 	google.golang.org/grpc v1.31.1 // indirect
+	golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed // indirect
 	google.golang.org/protobuf v1.25.0 // indirect
 	gopkg.in/ini.v1 v1.60.2
 	gopkg.in/mgo.v2 v2.0.0-20190816093944-a6b53ec6cb22 // indirect
 	gopkg.in/src-d/go-billy.v4 v4.3.2
 	gopkg.in/src-d/go-git.v4 v4.13.1
 	gopkg.in/yaml.v2 v2.3.0
 	zombiezen.com/go/log v1.0.1 // indirect
-)
+)

go.sum

@@ -531,8 +531,8 @@ golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd h1:xhmwyvizuTgC2qz7ZlMluP20u
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200610111108-226ff32320da h1:bGb80FudwxpeucJUjPYJXuJ8Hk91vNtfvrymzwiei38=
 golang.org/x/sys v0.0.0-20200610111108-226ff32320da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200831180312-196b9ba8737a h1:i47hUS795cOydZI4AwJQCKXOr4BvxzvikwDoDtHhP2Y=
-golang.org/x/sys v0.0.0-20200831180312-196b9ba8737a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed h1:WBkVNH1zd9jg/dK4HCM4lNANnmd12EHC9z+LmcCG4ns=
+golang.org/x/sys v0.0.0-20200810151505-1b9f1253b3ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.0.0-20170915090833-1cbadb444a80/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=