sbt/sbt package fail cause by directory

1.create a project named simpleApp
$cd simpleApp

$ find .
.
./simple.sbt
./src
./src/main
./src/main/scala
./src/main/scala/simpleApp.scala

$ ~/Software/spark-0.9.1/sbt/sbt
awk: fatal: cannot open file `./project/build.properties' for reading (No such file or directory)
Attempting to fetch sbt
/home/jpan/Software/spark-0.9.1/sbt/sbt: line 35: /sbt/sbt-launch-.jar: No such file or directory
/home/jpan/Software/spark-0.9.1/sbt/sbt: line 35: /sbt/sbt-launch-.jar: No such file or directory
Our attempt to download sbt locally to /sbt/sbt-launch-.jar failed. Please install sbt manually from http://www.scala-sbt.org/

it failed because sbt use relative path。