/usr/share/gocode/src/ is in golang-github-mitchellh-mapstructure-dev 0.0~git20170523.0.d0303fe-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gocode/src/github.com/
/usr/share/gocode/src/github.com/mitchellh/
/usr/share/gocode/src/github.com/mitchellh/mapstructure/
/usr/share/gocode/src/github.com/mitchellh/mapstructure/decode_hooks.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/decode_hooks_test.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/error.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/mapstructure.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/mapstructure_benchmark_test.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/mapstructure_bugs_test.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/mapstructure_examples_test.go
/usr/share/gocode/src/github.com/mitchellh/mapstructure/mapstructure_test.go