Faulty status page

[jchapuis]

Hey there, i'm struggling with kamon and was trying to bring up the status page but it's empty, some requests are failing

Here are my dependenccies

    val kamon = "2.7.5"

  "io.kamon" %% "kamon-bundle" % Versions.kamon,
  "io.kamon" %% "kamon-datadog" % Versions.kamon,
  "io.kamon" %% "kamon-http4s-0-23" % Versions.kamon,
  "io.kamon" %% "kamon-logback" % Versions.kamon

The requests are failing with

Failed to serve request due to: 

kamon.status.page.JsonMarshalling$BaseInfoJsonMarshalling$.toJson(JsonMarshalling.scala:74)
kamon.status.page.JsonMarshalling$BaseInfoJsonMarshalling$.toJson(JsonMarshalling.scala:71)
kamon.status.page.StatusPageServer.json(StatusPageServer.scala:89)
kamon.status.page.StatusPageServer.serve(StatusPageServer.scala:46)
kamon.lib.fi.iki.elonen.NanoHTTPD$HTTPSession.execute(NanoHTTPD.java:945)
kamon.lib.fi.iki.elonen.NanoHTTPD$ClientHandler.run(NanoHTTPD.java:192)

[jchapuis]

"java.lang.IllegalAccessError: failed to access class kamon.lib.com.grack.nanojson.JsonWriterBase from class kamon.status.page.JsonMarshalling$ModuleRegistryStatusJsonMarshalling$ (kamon.lib.com.grack.nanojson.JsonWriterBase and kamon.status.page.JsonMarshalling$ModuleRegistryStatusJsonMarshalling$ are in unnamed module of loader 'app')"

[ivantopo]

Hey @jchapuis, what Java/scala version are you using in that project?

[jchapuis]

Hey @jchapuis, what Java/scala version are you using in that project?

Hey Ivan! on JDK >=17 with Scala 3. I'm trying my luck with --add-opens at the moment but haven't found the workaround yet

[ivantopo]

Managed to reproduce this with Scala 3 only, the same versions on Scala 2.13 work as expected.

I have no idea why it happens, but just for testing I changed the rename rule so that nanojson ends up in the kamon.status.page package and it works fine like that. Weirdly enough, there were no issues with Scala 3 in the branch where I'm upgrading to the latest Kanela (see #1387) 🤷

Opened a PR with that simple workaround, will likely release it tomorrow as 2.7.6 before merging the big changes

[jchapuis]

@ivantopo great, thanks!