I realized that at least miniconda3-3.19.0 contains `xz` in it.

Basically I'd like to use system pakcage for `xz` command as much as
possible.

pyenv.d/which/anaconda.bash

@@ -101,6 +101,11 @@ EOS
   ## xsltproc
   cat <<EOS
 xsltproc
+EOS
+
+  # xz-utils
+  cat <<EOS
+xz
 EOS
 }