Filename too long sbt - scala

Question

I am getting an error saying I have a file that is too long in sbt.
[info] Compiling 29 Scala sources to /home/chris/dev/suredbits-core/target/scala-2.11/classes...
[error] File name too long
[error] one error found
[error] (compile:compile) Compilation failed
[error] Total time: 7 s, completed Feb 17, 2015 8:10:25 AM
How do I find out which file is too long so I can shorten the filename? I have added the compiler flag -Xmax-classfile-name and set it to 254.

Answer 1

If your /home is an encrypted file system (e.g. LUKS), you might run into this issue.
Setting max-classfile-name to 254 is the default (or it might be 255) - so you're not reducing it much. You should probably be considering something closer to a max length of 70 - 100. You can set it for all your projects by creating ~/.sbt/0.13/local.sbt with the scalac override:
scalacOptions ++= Seq("-Xmax-classfile-name","78")

Answer 2

This is how I solved my problem
mkdir /tmp/myproject-target
cd ~/workspace/myproject
rm -rf target
ln -s /tmp/myproject-target target

Answer 3

I encountered this problem in IntelliJ Ultimate 2016.1.2 (which resembles Intellij 14). I solved it by setting:
-Xmax-classfile-name 78
In File > Settings... > Build, Execution, Deployment > Compiler > Scala Compiler > Additional Compiler Options.
NOTE: there is a space between the option name and its value ("78"), not an equals sign.

Answer 4

Try using a shell script like this:
#!/bin/sh
for file in *; do {
echo -m "$file" | wc -m;
echo "$file"
}
done
Running this in your src/main/scala directory should show you which files have a name with more than 254 chars. I hope this answers your question.

Answer 5

Setting the file length limits might be unsafe, I could not find any official documentation that this solution is safe.
Using un-encrypted directory is not safe.
I want to offer a different approach:
install veracrypt (in ubuntu with apt)
create a non-encrypted directory (outside the encrypted user home dir)
create a veracrypt file container in the new directory
mount the container in
sbt works fine even if the mount point is in the encrypted directory)
It is possible to create the container with a complex password and mount on login
veracrypt -t --pim=0 --protect-hidden=no -k "" -p $PASSWORD $ENCRYPTED_CONTAINER $MOUNT_DIR