The startup script should set sbt.cygwin=true if running from cygwin.
This will set the terminal type properly for JLine if not already set.
If sbt.cygwin=false or unset and os.name includes "windows", JAnsi is
downloaded by the launcher and installed on standard out/err.
The value for jline.terminal is transformed from explicit jline.X to
the basic types "windows", "unix", or "none". Now that sbt uses JLine
2.0, these types are understood by both sbt's JLine and Scala's.
Older Scala versions shaded the classes but not the terminal property
so both couldn't be configured with a class name at the same time.
Support a definitive flag for Failure that ignores later failures
instead of appending them. This is useful to override the default
behavior of listing the failures of alternative parsers.
alias only parses the right hand side for tab completion help.
The assignment should happen whether or not the parse is successful because the
context may change by the time the alias is actually evaluated.
In particular, the 'set' command uses the loaded project for tab completion in 0.12.1.
When a .sbtrc file is processed, the project has not been loaded yet, so aliases
involving set fail. Wrapping the rhs in failOnException addresses this.
In the unsupported terminal mode, JLine treats a broken
stdin as an endless stream of empty lines. This is problematic
for idea-sbt-plugin: if the IntelliJ process is forcibly killed
and leaves the child SBT process running, it consumes considerable
CPU processing these.
Patching JLine itself would be the cleanest solution (the change
has already been applied to JLine 2), but I've shied away from that
and instead wrapped the InputStream that is read by JLine to
intercept the result of -1 from read(). When this happens, the
flat `inputEof` is set to true.