I have 2 sbt-android-scala projects. The first one is a single one:
$ ls -al
drwxr-xr-x 13 alex staff 442 Dec 24 20:44 .
drwxr-xr-x 4 alex staff 136 Dec 24 21:08 ..
drwxr-xr-x 12 alex staff 408 Dec 24 20:38 .git
-rw-r--r-- 1 alex staff 141 Dec 24 20:38 .gitignore
-rw-r--r-- 1 alex staff 115 Dec 24 20:38 .travis.yml
-rw-r--r-- 1 alex staff 664 Dec 24 20:38 CHANGES
-rw-r--r-- 1 alex staff 1418 Dec 24 20:38 LICENSE
-rw-r--r-- 1 alex staff 2491 Dec 24 20:38 README.md
-rw-r--r-- 1 alex staff 874 Dec 24 20:38 build.sbt
drwxr-xr-x 10 alex staff 340 Dec 24 20:38 notes
drwxr-xr-x 5 alex staff 170 Dec 24 20:43 project
drwxr-xr-x 3 alex staff 102 Dec 24 20:38 src
drwxr-xr-x 5 alex staff 170 Dec 25 01:17 target
The second one has sub-projects in it:
$ ls -al
drwxr-xr-x 23 alex staff 782 Dec 24 21:57 .
drwxr-xr-x 4 alex staff 136 Dec 24 21:08 ..
drwxr-xr-x 13 alex staff 442 Dec 24 21:57 .git
-rw-r--r-- 1 alex staff 44 Dec 24 21:57 .gitignore
-rw-r--r-- 1 alex staff 203 Dec 24 21:57 .gitmodules
-rw-r--r-- 1 alex staff 46 Dec 24 21:57 .sbtopts
-rw-r--r-- 1 alex staff 55 Dec 24 21:57 .sbtrc
-rw-r--r-- 1 alex staff 35119 Dec 24 21:57 LICENSE.md
-rw-r--r-- 1 alex staff 6964 Dec 24 21:57 README.md
-rw-r--r-- 1 alex staff 30626 Dec 24 21:57 RELEASE-NOTES.md
drwxr-xr-x 18 alex staff 612 Dec 24 21:57 my_prj1
-rw-r--r-- 1 alex staff 892 Dec 24 21:57 build.sbt
drwxr-xr-x 11 alex staff 374 Dec 24 21:57 common
drwxr-xr-x 11 alex staff 374 Dec 24 21:57 my_prj2
drwxr-xr-x 3 alex staff 102 Dec 24 21:57 my_prj3
drwxr-xr-x 7 alex staff 238 Dec 24 22:01 project
When I run sbt
in the 1st project, it compiles well, unlike in the 2nd one:
$ sbt
No java installations was detected.
Please go to http://www.java.com/getjava/ and download
But
$ echo $JAVA_HOME
/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home