/usr/share/gocode/src/golang.org/x/text/width/ is in golang-golang-x-text-dev 0.0~git20170627.0.6353ef0-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gocode/src/golang.org/x/text/width/common_test.go
/usr/share/gocode/src/golang.org/x/text/width/example_test.go
/usr/share/gocode/src/golang.org/x/text/width/gen.go
/usr/share/gocode/src/golang.org/x/text/width/gen_common.go
/usr/share/gocode/src/golang.org/x/text/width/gen_trieval.go
/usr/share/gocode/src/golang.org/x/text/width/kind_string.go
/usr/share/gocode/src/golang.org/x/text/width/runes_test.go
/usr/share/gocode/src/golang.org/x/text/width/tables.go
/usr/share/gocode/src/golang.org/x/text/width/tables_test.go
/usr/share/gocode/src/golang.org/x/text/width/transform.go
/usr/share/gocode/src/golang.org/x/text/width/transform_test.go
/usr/share/gocode/src/golang.org/x/text/width/trieval.go
/usr/share/gocode/src/golang.org/x/text/width/width.go