TODO

* update core Guile to handle Cygwin library versioning such as
  cygguile-ncurses-12.dll, so that we don't need to pass the
  -avoid-version flag in the linker.

* fix core Guile on MinGW. But really this should include changing to
  UCRT, which is non-trivial.

* update tools to use the version of Guile found by configure

* find the mysterious bug in guile-ncurses-shell where getch will
  fetch a few hex digits after the shell starts up

* verify on Hurd, MacOS someday
