scala “error: io error while decoding” “with utf-8”

Question

this thing keeps coming up I checked that all my source files are utf8 encoded, and Im using \'-encoding UTF8\' flag with both scalac and scala command line tools
any ideas?

Answer 1

I encountered this problem running sbt "test" with Main.scala, for the indicated reason that it wasn't saved in UTF-8. I fixed it by changing Eclipse Main.scala "File / Properties / Text file encoding / Other" to "UTF-8" and saving.

Answer 2

Just to document this, the problem is that the program was being run like this:

scala filename.class

Instead, it should be run like this:

scala package.hierarchy.Object

Where Object is the name of an main-containing object that you wish to run.

Answer 3

This will be rare, however in my case this happened because I had a few files that had file ownership set to the company I am consulting at. This not the normal file ownership under security but the microsoft azure protection encryption that you can disable using right click -> File ownership -> Personal (if there is a business domain set there, it is encrypted and needs to be decoded). Windows apps can open the file normally but using non-ms tools, like winrar and seemingly this case, it could not decode the file. Ideally there should be a way to work with the encrypted files but I'm not going to spend time on that here! :)

Answer 4

I was having this error trying to set a classpath to launch the scala interpreter like scala-2.8 /path/to/jars/*.

The solutions in this thread Setting multiple jars in java classpath solved my problem; apparently the interpreter was attempting to open a jar file as if it was a text file containing scala commands.

Actually, I noticed that just putting the classpath in quotes prevents this message. The message means it is trying to load a .jar file as a scala program to be interpreted. It can't since it's binary.

scala-2.8 "/path/to/jars/*" works fine. The classpath and asterisk is then expanded by Java, not the shell.