Performing:

$ git checkout origin/0.10.1

Then attempting to build using SBT fails with a java.lang.AssertionError. This is because of line 278 of build.scala. I suspect that because I checked out the remote instance of the branch, it could not detect the 'tracking' reference and failed at the assertion.

Performing:
$ git checkout 0.10.1

works because 0.10.1 is setup to track origin/0.10.1.

In short, we need a better error message here.

Portion of the trace:

> [debug] Scala compilation took 9.592334588 s [debug] Step 2 changed
> sources and immdediate dependencies:
> [debug] Set(/home/developer/daffodil_10.1/daffodil/project/build.scala)
> [debug] Non-trivial strongly connected components:
> [debug]
> [debug] Step 2 invalidated sources:
> [debug] Set(/home/developer/daffodil_10.1/daffodil/project/build.scala)
> [debug] Copy resource mappings:
> [debug]
> java.lang.AssertionError: assertion failed
> at scala.Predef$.assert(Predef.scala:146)
> at DaffodilBuild$$anonfun$14.apply(build.scala:278)
> at DaffodilBuild$$anonfun$14.apply(build.scala:247)
> at sbt.Init$Value$$anonfun$apply$6.apply(Settings.scala:329)
> at sbt.EvaluateSettings$$anonfun$sbt$EvaluateSettings$$constant$1.apply(INode.scala:158)
> at sbt.EvaluateSettings$$anonfun$sbt$EvaluateSettings$$constant$1.apply(INode.scala:158)
> at sbt.EvaluateSettings$MixedNode.evaluate0(INode.scala:177)
> at sbt.EvaluateSettings$INode.evaluate(INode.scala:132)
> at sbt.EvaluateSettings$$anonfun$sbt$EvaluateSettings$$submitEvaluate$1.apply$mcV$sp(INode.scala:64)
> at sbt.EvaluateSettings.sbt$EvaluateSettings$$run0(INode.scala:73)
> at sbt.EvaluateSettings$$anon$3.run(INode.scala:69)
> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:722)