I am trying to compile the scala/Play framework example application on my local machine, but I am getting compilation errors when trying to compile using the SBT console in IntelliJ:
error: scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
I also got this message in the event log related to different SBT versions:
14:48 Started sbt shell with sbt version 0.13.18 instead of 0.13.11 configured by project.
Update sbt version
Disable version override
Any suggestions on how to fix this?
For the first error
error: scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
You might want to try and ensure that you are using a compatible java version. Like #cbley suggested, try making you are using version 8 of the JDK.
For the second error
14:48 Started sbt shell with sbt version 0.13.18 instead of 0.13.11 configured by project.
Update sbt version
Disable version override
Its just suggesting you update the version of sbt (which is most likely declared in your build.properties file in a folder called project. You can just search for it by double tapping shift in IntelliJ. But you are safe to ignore it if you cloned some example repository as well.
check
Related
I am trying to run Play on Heroku...
The full error is:
play.api.UnexpectedException: Unexpected exception[RuntimeException: java.lang.UnsupportedClassVersionError: controllers/routes has been compiled by a more recent version of the Java Runtime (class file version 58.0), this version of the Java Runtime only recognizes class file versions up to 55.0] (58 is Java 14 and 55 is Java 11).
The Heroku help says:
Make sure you are using the correct JDK version by setting it in the system.properties file.
I added the following to system.proprties:
java.runtime.version=14.0.1.
And I can see it gets used by the Heroku compile. But I still get the error.
I thought that maybe the problem was the other way around so I also tried:
java.runtime.version=11.0.8
I also tried adding the following to application.conf
java.source=11.0.8
And for completeness java.source=14.0.1
When I run locally without Heroku (sbt compile stage) all is fine.
I have tried with the Play example from Heroku and also the Play example from Play (adding a procfile)... the result is the same.
The Play version is:
addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.2")
I tried putting in some older versions but Heroku failed to compile.
I went back to trying to get the Heroku version to run locally (rather than the other way around). From the resulting error message I found that sbt installed via brew adds a dependency to JDK 13:
SBT fails with `String.class is broken`
I followed the fix listed there and installed sbt using SDKMAN (instructions here:
https://www.scala-sbt.org/1.x/docs/Installing-sbt-on-Mac.html)
This got me to the next error which was due to "old SBT version":
java.lang.NullPointerException in project root running sbt
After fixing this, I can now run Play on Heroku and locally
I tried to run scala app in IJ community version 2018.3.6, and ran into this error:
Error:scalac: Multiple 'scala-library*.jar' files (scala-library-2.12.8.jar, scala-library-2.12.8.jar) in Scala compiler classpath in Scala SDK sbt: org.scala-lang:scala-library:2.12.8:jar
and I checked hte .idea/libraries folder saw:
sbt__org_scala_lang_scala_library_2_11_8.jar.xml
sbt__org_scala_lang_scala_library_2_12_8.jar.xml
after I delete sbt__org_scala_lang_scala_library_2_11_8.jar.xml still got the same error, then i deleted all 2.11.8 scala*.files still got hte same error
I also tried to open the same project in IJ community version 2019.2.4, it complained:
Cannot determine module type ("SBT_MODULE") for the following module:
there is no 'sbt' tool listed in Preference -> Build, Execution, Deployment -> Build Tools
anyone know how to get it work?
## FIX
i ended up to uninstall and reinstall Scala plugin in IJ 2019.2.4 to get it working again.
Scala newbie here: I am attempting to get started with Scala using Windows 10 (Pro 10.0.18362 Build 18362) Hyper-v Quick Create of Ubuntu (18.04.3 LTS). I installed the JRE and JDK (11.0.4). I installed IntelliJ IDEA 2019.2.4. I added the Plugin for Scala (plugin 2019.2.37). I have left the SBT Executor 1.2.1 disabled for now: it was enabled earlier but it does not seem to affect the results. I tried to create the HelloWorld application (see below). I added the Scala Framework to the Project and, after encountering the error below, the Mavin framework (adding Mavin did not help.) After correcting the error in bulid.sbt it looks like this:
import com.sun.tools.javac.resources.version
name := "HelloWorld"
version := "0.1"
scalaVersion := "2.13.1"
I create a Scala worksheet by right-click on scala folder and selecting Scala Worksheet:
object Hello extends App {
println("Hello, World!")
}
I get a pop-up saying Maven project needs to be imported. This succeeds quickly. I get a second one saying sbt project needs to be imported. This fails:
sbt.librarymanagement.ResolveException: Error downloading org.scala-sbt:zinc-compile-core_2.12:1.3.1
and this error accompanies it:
not found: https://repo.scala-sbt.org/scalasbt/sbt-plugin-releases/org.scala-sbt/util-position_2.12/1.3.2/ivys/ivy.xml
The first ResolveException appears to be about a part of Mavin, but that should be present. This error message is followed by many other "not found" errors, but I assume they all stem from the above errors or are related. I cannot seem to find a solution: most of the information and examples on IntelliJ IDEA Scala on the web are several years (editions) out of date.
It appears Maven apps are to be deployed to Apache Spark. Not my intention, but in the Mavin panel I can successfully clean, validate and compile.
When I Run the Hello.sc app, I get this:
/snap/intellij-idea-community/185/jbr/bin/java -javaagent:/snap/intellij-idea-community/185/lib/idea_rt.jar=37033:/snap/intellij-idea-community/185/bin -Dfile.encoding=UTF-8 -classpath /home/perfwise/ideaProjects/HelloWorld/target/classes:/home/perfwise/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.13.1.jar:/home/perfwise/.ivy2/cache/org.scala-lang/scala-reflect/jars/scala-reflect-2.13.1.jar:/home/perfwise/.ivy2/cache/org.scala-lang/scala-library/srcs/scala-library-2.13.1-sources.jar:/home/perfwise/.ivy2/cache/org.scala-lang/scala-reflect/srcs/scala-reflect-2.13.1-sources.jar Hello
Error: Could not find or load main class Hello
Caused by: java.lang.ClassNotFoundException: Hello
Process finished with exit code 1
I would have expected this to work. Any pointers will be much appreciated.
I have (multiple times) tried to install SBT-0.13.8 from the SBT download page via the SBT-0.13.8-MSI button and I always end up getting an SBT version which shows the following output
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0
[info] Loading project definition from C:\Users\Tina\Desktop\example\project\project
error: error while loading CharSequence, class file 'C:\Program Files\Java\jre1.
8.0_20\lib\rt.jar(java/lang/CharSequence.class)' is broken (bad constant pool tag 15 at byte 1470)
[error] Type error in expression
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? i
[warn] Ignoring load failure: no project loaded.
> about
[info] This is sbt 0.12.4
[info] No project is currently loaded
[info] sbt, sbt plugins, and build definitions are using Scala 2.9.2
SBT produces an error message and (!) shows itself as version 0.12.4.!!!
I really made sure that I have no other version of SBT installed and I even made a reboot before re-installing it but nothing changed. SBT files have a creation date of March, 21, 2015. This seems to be the newest version but why does this version show up as 0.12.4 and does not work with JDK1.8?
Looks like the directory you're in is wrong, you want to launch sbt from C:\Users\Tina\Desktop\example\project not C:\Users\Tina\Desktop\example\project\project (note 1 project less).
The second problem you're having is you're trying to use sbt 0.12.4 with Java 8. sbt 0.12.4 uses (as can be seen from the output) Scala 2.9.2 which doesn't work with Java 8. I would recommend migrating to sbt 0.13.8, but if not you could always downgrade to Java 7.
Edit after comments below
The progfun Coursera course download is still configured with sbt
0.12.4 which you're having trouble building because you are using Java 8.
I had a quick go at trying to see if upgrading the project to 0.13.8 would work (FYI it involves editing project/build.properties), but then plugins need to be upgraded, then meta-build code needed to be changed because of namespace changes..
Unless you're willing to experiment more and work you're way through the various changes required to use latest sbt and latest Java (which is what I would do if this were for myself), I would recommend as an alternative to:
Downgrade to Java 7
Notify the relevant people involved in running the course that the source material should be updated as it demonstrably does not work on latest, stable Java.
If your default Java is Java 8 but you want to switch to Java 7 for this out-of-date project setup, you need to create an .sbtopts file at the root of the project containing (note: on separate lines!):
-java-home
C:\Users\Tina\PATH\TO\YOUR\JAVA\HOME
I'm trying to develop on the Scala compiler project with the help of ScalaIDE. I followed this guide to set up the development environment. When I now try to build the mentioned projects, the reflect project won't get built. Instead, I get the following error via the console output:
uncaught exception during compilation: scala.reflect.internal.MissingRequirementError reflect Unknown Scala Problem
Having tried the provided ANT script of the project via the console, everything seems to work fine.
Does anyone know if I'm missing a hidden compiler flag, dependency or something like this?
Thanks!
With the IDE for Scala 2.10 you can only build the 2.10.x branch of the Scala compiler. If you want to work on master, you need to install a 2.11-based version of the IDE. We don't publicise IDE for 2.11 nightlies yet, but they are available at:
http://download.scala-ide.org/nightly/scala-ide-master-2.11.0-SNAPSHOT/