/usr/share/gocode/src/golang.org/x/text/encoding/testdata/ 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/encoding/testdata/candide-gb18030.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/candide-utf-16le.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/candide-utf-32be.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/candide-utf-8.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/candide-windows-1252.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/rashomon-euc-jp.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/rashomon-iso-2022-jp.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/rashomon-shift-jis.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/rashomon-utf-8.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-gb-levels-1-and-2-hz-gb2312.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-gb-levels-1-and-2-utf-8.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-simplified-gbk.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-simplified-utf-8.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-traditional-big5.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/sunzi-bingfa-traditional-utf-8.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/unsu-joh-eun-nal-euc-kr.txt
/usr/share/gocode/src/golang.org/x/text/encoding/testdata/unsu-joh-eun-nal-utf-8.txt