When I try to run a test file through sbt-shell, it runs fine(sbt testOnly a.b.MySpec)
But when I try to run the same test file through intellij IDEA(2021.2.2 CE)'s green arrow run button, I gives this error
DriverFs2Grpc is already defined as trait DriverFs2Grpc
trait DriverFs2Grpc[F[_], A] {
My project is a multi module sbt, scala project with the following structure.
DriverFs2Grpc trait mentioned in the error message is an auto generated trait which resides in target/scala-2.12/src_managed/main/fs2-grpc/packageX/DriverFs2Grpc.scala
IntelliJ is trying to create a duplicate of the same file for some reason.
I think this is caused by an invalid source configuration.
My issue is similar to the question asked here, but still I couldn't figure it out.
Appreciate any help to resolve this issue.
Related
I just created a simple helloworld scala project in Intellij. My main class is simply printing Hello World -
package xx.yy.zz
object HelloWorld{
def main(args: Array[String]): Unit = {
System.out.print("Hello World!")
}
}
My project structure
scala-test
|_src
|_main
|_scala
|_xx
|_yy
|_zz
|_HelloWorld
In the project structure settings, I have "scala" as my source folder. I am able to select my main class correctly in the application run configuration I created. So far so good. After this, when I try to run my run configuration, I get the dreaded error -
Error: Could not find or load main class xx.yy.zz.HelloWorld
At this point, I have tried all the things I could find on google like invalidating cache, reloading project, switching source folder to be "src" instead of "scala" and many others that I have lost track of by now. Please help!!
I didn't investigate the reasons for this issue but as a workaround, you can compile the project via sbt/shell sbt before running via Intellij.
I changed my Scala version from 2.10.x to 2.11.8. I am getting some compilation issues. I tried, but still not able to resolve because I am poor in Scala and sbt.
WebService.scala:36: can't expand macros compiled by previous versions of Scala
[error] logger.error(s"WebService.getSiteData(${Id}): Unknown Error, Error Message: $e")
What might be the issue here?
I resolved this issue but it not a single thing, I did couple of things:
First I gone through the error location in WebService.scala.
Then to the corresponding "Logger" class.
I check from which jar that "Logger" class coming.
I found that it referring to some thing else jar than what I am expecting.
That jar is coming from one of my dependent project (modules) so in build.sbt, those dependent jars I excluded that wrong jar which I found.
After I changed the code in WebService.scala, I removed that import for logger and added new import having Logger what I expecting. I did same all the other places in my project.
WebService.scala:36: can't expand macros compiled by previous versions of Scala
[error] logger.error(s"WebService.getSiteData(${Id}): Unknown Error, Error Message: $e")
This is not particular to logger issue. If you are getting "can't expand macros compiled by previous versions of Scala" issue", you have to do same procedure for corresponding to your error (my case logger).
First time, I search online regarding this issue, I found same issue facing lot of people, but different library classes (I face Logger class issue).
I have my very first Scala program, which is as simple as:
object HelloWorld{
def main(args: Array[String]){
println("Hello world!")
}
}
I then try to compile it like so:
$ scalac HelloWorld.scala
And it compiles without any error messages. When however I try to run it like so:
$ scala HelloWorld
I get an error message:
No such file or class on classpath: HelloWorld
To implement this, I followed this tutorial and to solve the emerged error, I followed this suggestion. However,
$ scala objects.HelloWorld
also does not work. I know many people will now start heavily voting down my question and asking questions - have you ever tried to read some books on it (Yes, I did. I've read Horstman book for beginners, but it does not contain any information on compiling programs under Ubuntu). Still, I hope someone could help.
(This was a comment before, and I rephrased it to a response.)
You've done everything right, except for the last step: Use the java command instead of the scala command.
scala is the Scala REPL. No separate run command is required for Scala code, because it compiles to regular Java bytecode.
So try: java HelloWorld
For more complex programs that make use of the Scala library however, you need to include the Scala runtime library in the classpath. So, on the long run, it is beneficiary to use a tool like SBT, as pointed out by #roterl in the comments.
The answer saying that the scala command is just for the REPL is incorrect. You can see from the man page entry for scala (http://www.scala-lang.org/files/archive/nightly/docs-2.10.2/manual/html/scala.html) that it is intended to be used in the same way as the java command with the added flexibility that it will run the REPL, scripts, or compiled applications.
As some of the comments have indicated, this is almost certainly a path issue, which means that it requires more information to diagnose. One thing you can check is whether the scalac command produced a .class file in your current directory. If that is in the directory where you are running scala then the comments about needing . in your classpath are almost certainly correct.
I have Intellij-IDEA 13.1.2. [edited, previously 13.0.2]
I use the scala-plugin.
I'm trying to use worksheets to evaluate code.
But all I got are two errors :
bad macro impl binding: versionFormat is supposed to be there
Unable to read an event from: rO0ABXNyADVvcmcuamV0YnJhaW5zLmpwcy5pbmNyZW1lbnRhbC...
I can run the scala console normally and execute my code in it,
but the worksheet doesn't function.
If my code is incorrect, it outputs an error indicating the interpreter failed to parse my code. I got the "bad macro impl binding" error only if my code is correct.
I tried creating a new project, but it didn't work.
I followed tutorial to configure scala in intellij but it didn't help either.
Is there an important configuration step I may have missed ? What does that error mean ?
EDIT : I tried the simplest thing in my worksheet like 1 or var x = 1 or println("Hello World!")
EDIT2: I'm not sure what I changed but now I have another error :
Error:error while loading MacroPrinter, class file needed by MacroPrinter is missing.
reference value macros of package reflect refers to nonexisting symbol.
UPDATE: Now it works fine under Intellij 13.1.5, Scala plugin 0.41.2 with both scala-2.10 and 2.11
I had the "Unable to read an event from" issue and switching from Scala 2.11.0 to Scala 2.10.4 fixed it for me.
I've shared a workaround in a similar question and I think it can work for this question as well:
I'm having the same issue with latest Idea and Scala plugin.
It seems that the worksheet has a problem executing any line which evaluates to Unit. Assigning is Unit, that's why your tableTest(0) = "zero" fails.
I've temporarily solved it with the following workaround:
this line will fail with error Error:Unable to read an event from:...
println("Will fail")
You can fix it by defining this helper method and using it for any Unit expression:
def unit(f: => Unit): String = {f; ""}
unit(println("Will work"))
You just have to ignore the line it generates in the output panel with res0: String =
You also can put this method in some object and import in any WS you need.
I am using IntelliJIDEA 13.1.2 and Scala Plugin 0.36.431. I tried to create a Scala Non-SBT project and created a worksheet file, then I met the "bad macro impl binding" problem. But if I created a Scala SBT project with a worksheet file, it worked well.
After updating to IntelliJ 13.1.5 build 135.1289 with JRE 1.7.0_60 and Scala 2.11.0 I had the same issue.
I fixed the problem by disabling the checkbox in settings -> IDE Settings -> Scala -> "Run compile server".
I've been trying to get a Scala hello world example running on Eclipse using the Scala plugin. Writing the following:
package scala_test
object Test {
def main(args: Array[String]) {
println("Hello, World")
}
}
produces the following error:
<console>:1: error: eof expected but '}' found.
}
^
I've tried this on both a Windows machine and a Mac (both were using Eclipse 3.7). I've tried commenting out the function definition (just leaving an empty body for the Test object) and the error still occurs. Any ideas as to what might cause this?
You need to see output in console, not in scala interpreter.
Just right click on scala file and select "run as scala application".
Make sure you have added the Scala nature to the project. On some versions of the plugin, that option is only available from the contextual "Configuration" menu if the Scala perspective is active. Your project icon should have an "S" instead of a "J" in the corner if you have made this change.
Make sure its in the right package, runs for me. I'm using this plugin
http://scala-ide.org/