Ref https://github.com/sbt/sbt/issues/4121
sbt already has the facility to trim stack traces. This sets the trace level of the background run, which fixes the upper half of the `run` stacktrace.
```
[error] (run-main-0) java.lang.Exception
[error] java.lang.Exception
[error] at Hello$.delayedEndpoint$Hello$1(Hello.scala:5)
[error] at Hello$delayedInit$body.apply(Hello.scala:1)
[error] at scala.Function0.apply$mcV$sp(Function0.scala:34)
[error] at scala.Function0.apply$mcV$sp$(Function0.scala:34)
[error] at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
[error] at scala.App.$anonfun$main$1$adapted(App.scala:76)
[error] at scala.collection.immutable.List.foreach(List.scala:389)
[error] at scala.App.main(App.scala:76)
[error] at scala.App.main$(App.scala:74)
[error] at Hello$.main(Hello.scala:1)
[error] at Hello.main(Hello.scala)
[error] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[error] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error] at java.lang.reflect.Method.invoke(Method.java:498)
[error] java.lang.RuntimeException: Nonzero exit code: 1
[error] at sbt.Run$.executeTrapExit(Run.scala:127)
[error] at sbt.Run.run(Run.scala:77)
[error] at sbt.Defaults$.$anonfun$bgRunTask$5(Defaults.scala:1254)
[error] at sbt.Defaults$.$anonfun$bgRunTask$5$adapted(Defaults.scala:1249)
[error] at sbt.internal.BackgroundThreadPool.$anonfun$run$1(DefaultBackgroundJobService.scala:377)
[error] at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
[error] at scala.util.Try$.apply(Try.scala:209)
[error] at sbt.internal.BackgroundThreadPool$BackgroundRunnable.run(DefaultBackgroundJobService.scala:299)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] at java.lang.Thread.run(Thread.java:748)
[error] (Compile / run) Nonzero exit code: 1
```
The bottom half requires a similar fix to the foreground log.
Fixes https://github.com/sbt/sbt/issues/3508
This forks an instance of sbt in the background when it's not running already.
```
$ time sbt -client compile
Getting org.scala-sbt sbt 1.2.0-SNAPSHOT (this may take some time)...
:: retrieving :: org.scala-sbt#boot-app
confs: [default]
79 artifacts copied, 0 already retrieved (28214kB/130ms)
[info] entering *experimental* thin client - BEEP WHIRR
[info] server was not detected. starting an instance
[info] waiting for the server...
[info] waiting for the server...
[info] server found
> compile
[success] completed
sbt -client compile 9.25s user 2.39s system 33% cpu 34.893 total
$ time sbt -client compile
[info] entering *experimental* thin client - BEEP WHIRR
> compile
[success] completed
sbt -client compile 3.55s user 1.68s system 107% cpu 4.889 total
```
There's also a special case for aliases that will try to resolve
the target of the alias to a task key if possible and display the
output of that key if found.
see https://github.com/sbt/sbt/issues/2881
Fixes https://github.com/sbt/sbt/issues/1502
This adds `--addPluginSbtFile=<file>` command, which adds the given .sbt file to the plugin build.
Using this mechanism editors or IDEs can start a build with required plugin.
```
$ cat /tmp/extra.sbt
addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.7")
$ sbt --addPluginSbtFile=/tmp/extra.sbt
...
sbt:helloworld> plugins
In file:/xxxx/hellotest/
...
sbtassembly.AssemblyPlugin: enabled in root
```
I spent a lot of time debugging why it took 5 seconds to run tests each
time. It turns out that if the hostname is not set explicitly on os x,
then getaddrinfo takes 5 seconds to try (and fail) to resolve the dns
entry for the localhostname. This is easily fixed by setting the
hostname, but it is not at all easy to figure out that a slow hostname
lookup is the reason why tests are slow to start.
I don't know if this is a common issue on other platforms, so only issue
the warning on OS X.
It turns out that `syntaxAnalyzer.UnitParser()` in global now also
needs to be synchronized. The alternative is adding `synchronizeNames = true`
in the global constructor, but that already proved unreliable in the
case of #3743 (see comment https://github.com/sbt/sbt/issues/3170#issuecomment-355218833)