/usr/share/go-1.8/src/go/build/ is in golang-1.8-src 1.8.3-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/go-1.8/src/go/build/build.go
/usr/share/go-1.8/src/go/build/build_test.go
/usr/share/go-1.8/src/go/build/deps_test.go
/usr/share/go-1.8/src/go/build/doc.go
/usr/share/go-1.8/src/go/build/read.go
/usr/share/go-1.8/src/go/build/read_test.go
/usr/share/go-1.8/src/go/build/syslist.go
/usr/share/go-1.8/src/go/build/syslist_test.go
/usr/share/go-1.8/src/go/build/testdata/
/usr/share/go-1.8/src/go/build/testdata/empty/
/usr/share/go-1.8/src/go/build/testdata/empty/dummy
/usr/share/go-1.8/src/go/build/testdata/multi/
/usr/share/go-1.8/src/go/build/testdata/multi/file.go
/usr/share/go-1.8/src/go/build/testdata/multi/file_appengine.go
/usr/share/go-1.8/src/go/build/testdata/other/
/usr/share/go-1.8/src/go/build/testdata/other/file/
/usr/share/go-1.8/src/go/build/testdata/other/file/file.go
/usr/share/go-1.8/src/go/build/testdata/other/main.go
/usr/share/go-1.8/src/go/build/zcgo.go