VTA chisel build error

I’d run make run_chisel in app/tsim_example directory, and I got this error.

[info] Updating
[info] Resolved  dependencies
[warn]
[warn] 	Note: Unresolved dependencies path:
[error] sbt.librarymanagement.ResolveException: Error downloading edu.washington.cs:vta_2.11:0.1.0-SNAPSHOT
[error]   Not found
[error]   Not found
[error]   not found: /home/thuako/.ivy2/local/edu.washington.cs/vta_2.11/0.1.0-SNAPSHOT/ivys/ivy.xml
[error]   not found: https://repo1.maven.org/maven2/edu/washington/cs/vta_2.11/0.1.0-SNAPSHOT/vta_2.11-0.1.0-SNAPSHOT.pom
[error]   not found: https://oss.sonatype.org/content/repositories/snapshots/edu/washington/cs/vta_2.11/0.1.0-SNAPSHOT/vta_2.11-0.1.0-SNAPSHOT.pom
[error]   not found: https://oss.sonatype.org/content/repositories/releases/edu/washington/cs/vta_2.11/0.1.0-SNAPSHOT/vta_2.11-0.1.0-SNAPSHOT.pom
[error] 	at lmcoursier.CoursierDependencyResolution.unresolvedWarningOrThrow(CoursierDependencyResolution.scala:245)
[error] 	at lmcoursier.CoursierDependencyResolution.$anonfun$update$34(CoursierDependencyResolution.scala:214)
[error] 	at scala.util.Either$LeftProjection.map(Either.scala:573)
[error] 	at lmcoursier.CoursierDependencyResolution.update(CoursierDependencyResolution.scala:214)
[error] 	at sbt.librarymanagement.DependencyResolution.update(DependencyResolution.scala:60)
[error] 	at sbt.internal.LibraryManagement$.resolve$1(LibraryManagement.scala:52)
[error] 	at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$12(LibraryManagement.scala:102)
[error] 	at sbt.util.Tracked$.$anonfun$lastOutput$1(Tracked.scala:69)
[error] 	at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$20(LibraryManagement.scala:115)
[error] 	at scala.util.control.Exception$Catch.apply(Exception.scala:228)
[error] 	at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11(LibraryManagement.scala:115)
[error] 	at sbt.internal.LibraryManagement$.$anonfun$cachedUpdate$11$adapted(LibraryManagement.scala:96)
[error] 	at sbt.util.Tracked$.$anonfun$inputChanged$1(Tracked.scala:150)
[error] 	at sbt.internal.LibraryManagement$.cachedUpdate(LibraryManagement.scala:129)
[error] 	at sbt.Classpaths$.$anonfun$updateTask0$5(Defaults.scala:2942)
[error] 	at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error] 	at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error] 	at sbt.std.Transform$$anon$4.work(Transform.scala:67)
[error] 	at sbt.Execute.$anonfun$submit$2(Execute.scala:280)
[error] 	at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19)
[error] 	at sbt.Execute.work(Execute.scala:289)
[error] 	at sbt.Execute.$anonfun$submit$1(Execute.scala:280)