Unclear error message when configuration attribute is not properly set

[Gedochao]

I got the following error, when running scalafix with Scala 3.7.0-RC3:

error: The ExplicitResultTypes rule was compiled with a different Scala 3 minor (3.6) than the target sources (3.7). To fix this problem, make sure you are running the latest version of Scalafix. If that is the case, either change your build to stick to the Scala 3 LTS or Next versions supported by Scalafix, or enable ExplicitResultTypes.fetchScala3CompilerArtifactsOnVersionMismatch in .scalafix.conf in order to try to load what is needed dynamically.

But even with scalafix.conf:

rules = [
  DisableSyntax,
  LeakingImplicitClassVal,
  NoValInForComprehension,
  ExplicitResultTypes,
  OrganizeImports
]
ExplicitResultTypes.fetchScala3CompilerArtifactsOnVersionMismatch

I get:

Exception in thread "main" java.lang.IllegalArgumentException: 9 is not a valid line number, allowed [0..8]
        at metaconfig.Input.lineToOffset(Input.scala:33)
        at metaconfig.Position.lineContent(Position.scala:48)
        at metaconfig.Position.pretty(Position.scala:21)
        at metaconfig.ConfError$$anon$8.<init>(ConfError.scala:125)
        at metaconfig.ConfError$.parseError(ConfError.scala:125)
        at metaconfig.typesafeconfig.TypesafeConfig2Class$.gimmeSafeConf(TypesafeConfig2Class.scala:62)
        at metaconfig.typesafeconfig.TypesafeConfig2Class$.gimmeConfFromFile(TypesafeConfig2Class.scala:24)
        at metaconfig.Hocon$.fromInput(Hocon.scala:8)
        at metaconfig.Input$InputImplicits.parse(Input.scala:92)
        at metaconfig.Conf$.parseInput(Conf.scala:65)
        at scalafix.internal.v1.Args.fileConfig(Args.scala:235)
        at scalafix.internal.v1.Args.baseConfig(Args.scala:215)
        at scalafix.internal.v1.Args.validate(Args.scala:417)
        at scalafix.internal.v1.MainOps$.run(MainOps.scala:73)
        at scalafix.v1.Main$.run(Main.scala:34)
        at scalafix.v1.Main$.main(Main.scala:25)
        at scalafix.cli.Cli$.main(Cli.scala:9)
        at scalafix.cli.Cli.main(Cli.scala)

Running with Scala CLI nightly (same behaviour on v1.7.1), Scalafix 0.14.2:

scala-cli  fix . --power -S 3.7.0-RC3
# Running built-in rules...
# Writing project.scala
# Built-in rules completed.
# Running scalafix rules...
# Compiling project (Scala 3.7.0-RC3, JVM (17))
# Compiled project (Scala 3.7.0-RC3, JVM (17))
# Compiling project (test, Scala 3.7.0-RC3, JVM (17))
# Compiled project (test, Scala 3.7.0-RC3, JVM (17))
# Exception in thread "main" java.lang.IllegalArgumentException: 9 is not a valid line number, allowed [0..8]
#         at metaconfig.Input.lineToOffset(Input.scala:33)
#         at metaconfig.Position.lineContent(Position.scala:48)
#        at metaconfig.Position.pretty(Position.scala:21)
#        at metaconfig.ConfError$$anon$8.<init>(ConfError.scala:125)
#         at metaconfig.ConfError$.parseError(ConfError.scala:125)
#         at metaconfig.typesafeconfig.TypesafeConfig2Class$.gimmeSafeConf(TypesafeConfig2Class.scala:62)
#         at metaconfig.typesafeconfig.TypesafeConfig2Class$.gimmeConfFromFile(TypesafeConfig2Class.scala:24)
#         at metaconfig.Hocon$.fromInput(Hocon.scala:8)
#        at metaconfig.Input$InputImplicits.parse(Input.scala:92)
#         at metaconfig.Conf$.parseInput(Conf.scala:65)
#        at scalafix.internal.v1.Args.fileConfig(Args.scala:235)
#         at scalafix.internal.v1.Args.baseConfig(Args.scala:215)
#         at scalafix.internal.v1.Args.validate(Args.scala:417)
#         at scalafix.internal.v1.MainOps$.run(MainOps.scala:73)
#         at scalafix.v1.Main$.run(Main.scala:34)
#         at scalafix.v1.Main$.main(Main.scala:25)
#         at scalafix.cli.Cli$.main(Cli.scala:9)
#         at scalafix.cli.Cli.main(Cli.scala)
# scalafix rules failed.

[bjaglin]

Hi @Gedochao , thanks for the report!

Can you try setting an explicit value to the HOCON key ?

scalafix/scalafix-tests/input/src/main/scala-3/test/explicitResultTypesRunAcrossMinors/FetchScala3CompilerArtifactsOnVersionMismatch.scala

Line 4 in b6943bf

ExplicitResultTypes.fetchScala3CompilerArtifactsOnVersionMismatch = true

[bjaglin]

FTR, I am waiting for 3.7.0 final to cut a release with static, built-in support #2211

[Gedochao]

Ah yes, thanks @bjaglin!
Awkward, indeed that fixes it. Although I guess it shouldn't have crashed, so there's a bug there still 😅

[bjaglin]

Yes, it looks like a problem metaconfig does not handle missing values for trailing attributes... I assume you would have gotten a better error message if you had added the attribute above?