Incremental compiler didn't have any explicit logic to handle
cancelled compilation so it would go into inconsistent state.
Specifically, what would happen is that it would treat cancelled
compilation as a compilation that finished normally and try to
produce a new Analysis object out of partial information collected
in AnalysisCallback. The most obvious outcome would be that the
new Analysis would contain latest hashes for source files. The
next time incremental compiler was asked to recompile the same files
that it didn't recompile due to cancelled compilation it would think
they were already successfully compiled and would do nothing.
We fix that problem by following the same logic that handles compilation
errors, cleans up partial results (produced class files) and makes sure
that no Analysis is created out of broken state.
We do that by introducing a new exception `CompileCancelled`
and throwing it at the same spot as an exception signalizing compilation
errors is being thrown. We also modify `IncrementalCompile` to
catch that exception and gracefully return as there was no compilation
invoked.
NOTE: In case there were compilation errors reported _before_
compilation cancellations was requested we'll still report them
using an old mechanism so partial errors are not lost in case
of cancelled compilation.
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.
Set sbt.task.timings=true to print timings for tasks.
This sample progress handler shows how to get names for tasks and
deal with flatMapped tasks. There are still some tasks that make
it through as anonymous, which needs to be investigated.
A setting to provide a custom handler should come in a subsequent commit.
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.