src/Pure/Admin/build_cygwin.scala
22 months ago wenzelm 2017-09-30 updated to x86_64-cygwin;
23 months ago wenzelm 2017-08-28 updated to cygwin-20170828, which is close to Cygwin 2.8.2-1;
2017-02-28 wenzelm 2017-02-28 proper Isabelle/Scala tool;