Cygwin
======

* https://www.cygwin.com/

* Mirror with many old versions (not setup.ini)
  https://ftp.eq.uc.pt/software/pc/prog/cygwin

* Local snapshots:
  http://isabelle.in.tum.de/cygwin  (Isabelle2012)
  http://isabelle.in.tum.de/cygwin_2013  (Isabelle2013)
  http://isabelle.in.tum.de/cygwin_2013-1  (Isabelle2013-1 and Isabelle2013-2)
  http://isabelle.in.tum.de/cygwin_2014  (Isabelle2014)
  http://isabelle.in.tum.de/cygwin_2015  (Isabelle2015)
  http://isabelle.in.tum.de/cygwin_2016  (Isabelle2016)
  http://isabelle.in.tum.de/cygwin_2016-1  (Isabelle2016-1)
  http://isabelle.in.tum.de/cygwin_2017  (Isabelle2017)
  https://isabelle.sketis.net/cygwin_2018  (Isabelle2018)

* Apache2 redirects for virtual host isabelle.conf:
  Redirect /cygwin/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/release
  Redirect /cygwin_2013/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/release
  Redirect /cygwin_2013-1/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/release
  Redirect /cygwin_2013-1/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2014/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2015/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2015/x86_64/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86_64/release
  Redirect /cygwin_2016/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2016/x86_64/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86_64/release
  Redirect /cygwin_2016-1/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2016-1/noarch/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/noarch/release
  Redirect /cygwin_2017/x86/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2017/x86_64/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/x86_64/release
  Redirect /cygwin_2017/noarch/release http://ftp.eq.uc.pt/software/pc/prog/cygwin/noarch/release
  Redirect /cygwin_2018/x86/release https://ftp.eq.uc.pt/software/pc/prog/cygwin/x86/release
  Redirect /cygwin_2018/x86_64/release https://ftp.eq.uc.pt/software/pc/prog/cygwin/x86_64/release
  Redirect /cygwin_2018/noarch/release https://ftp.eq.uc.pt/software/pc/prog/cygwin/noarch/release

* Quasi-component: "isabelle build_cygwin" (as Administrator)

* SSH server:

  - run Cygwin terminal as Administrator

  - run ssh-host-config

    StrictMode: yes
    privilege separation: yes
    new local account 'sshd': yes
    sshd as a service: yes
    different name (than cyg_server): no
    new privileged account cyg_server: yes

  - mkpasswd -l > /etc/passwd
    mkgroup -l > /etc/group

    passwd -R USER