LastOnEmptyPath when installing in Alpine

[DavidPerezIngeniero]

Version(s)

Describe the bug
I'm following this guide to install scala-cli on Alpine:
https://scala-cli.virtuslab.org/install

wget -q -O scala-cli.gz  https://github.com/Virtuslab/scala-cli/releases/latest/download/scala-cli-x86_64-pc-linux-static.gz && gunzip scala-cli.gz
chmod +x scala-cli
mv scala-cli /usr/bin/

It works ok, but when trying to run it:

# scala-cli repl
Error: os.PathError$LastOnEmptyPath: empty path has no last segment
For more details, please see '/.scala-build/stacktraces/1708946925-1039453487471597717.log'

# cat /.scala-build/stacktraces/1708946925-1039453487471597717.log
os.PathError$LastOnEmptyPath: empty path has no last segment
  os.PathError$LastOnEmptyPath$.apply(Path.scala:228)
  os.BasePathImpl.last$$anonfun$1(Path.scala:210)
  scala.Option.getOrElse(Option.scala:201)
  os.BasePathImpl.last(Path.scala:210)
  os.BasePathImpl.last$(Path.scala:190)
  os.Path.last(Path.scala:483)
  os.BasePathImpl.baseName(Path.scala:205)
  os.BasePathImpl.baseName$(Path.scala:190)
  os.Path.baseName(Path.scala:483)
  scala.build.input.Inputs$.empty(Inputs.scala:469)
  scala.cli.commands.repl.Repl$.default$1$$anonfun$1(Repl.scala:108)
  scala.Option.getOrElse(Option.scala:201)
  scala.cli.commands.repl.Repl$.default$1(Repl.scala:109)
  scala.cli.commands.repl.Repl$.$anonfun$9(Repl.scala:111)
  scala.build.input.Inputs$.apply(Inputs.scala:442)
  scala.cli.commands.shared.SharedOptions$.inputs(SharedOptions.scala:680)
  scala.cli.commands.shared.SharedOptions.inputs(SharedOptions.scala:600)
  scala.cli.commands.repl.Repl$.runCommand(Repl.scala:111)
  scala.cli.commands.repl.Repl$.runCommand(Repl.scala:105)
  scala.cli.commands.ScalaCommand.run(ScalaCommand.scala:368)
  scala.cli.commands.ScalaCommand.run(ScalaCommand.scala:350)
  caseapp.core.app.CaseApp.main(CaseApp.scala:157)
  scala.cli.commands.ScalaCommand.main(ScalaCommand.scala:335)
  caseapp.core.app.CommandsEntryPoint.main(CommandsEntryPoint.scala:166)
  scala.cli.ScalaCliCommands.main(ScalaCliCommands.scala:125)
  scala.cli.ScalaCli$.main0(ScalaCli.scala:269)
  scala.cli.ScalaCli$.main(ScalaCli.scala:108)
  scala.cli.ScalaCli.main(ScalaCli.scala)

To Reproduce

docker run -ti --rm --entrypoint ash bellsoft/liberica-openjdk-alpine:21.0.2-cd
wget -q -O scala-cli.gz  https://github.com/Virtuslab/scala-cli/releases/latest/download/scala-cli-x86_64-pc-linux-static.gz && gunzip scala-cli.gz
chmod +x scala-cli
mv scala-cli /usr/bin/

Expected behaviour
I can use scala-cli.

[DavidPerezIngeniero]

In addition, it would be interesting to execute:

rm -f scala-cli.gz

[DavidPerezIngeniero]

Same problem happens with this image:

docker run -ti --rm --entrypoint ash alpine

Latest alpine 3.19.1.

[DavidPerezIngeniero]

Source code of Path.scala:
https://github.com/com-lihaoyi/os-lib/blob/main/os/src/Path.scala

[francisdb]

@Gedochao we are encountering this issue when trying to build the scala sbt docker image since Scala 3.5.0. Any hints on how to fix this? See sbt/docker-sbt#298

root@00eff3a8e8f5:/# scala
Error: os.PathError$LastOnEmptyPath: empty path has no last segment
For more details, please see '/.scala-build/stacktraces/1724705569-3531744079478753600.log'

edit: a workaround is not running a script in the fs root

[francisdb]

Also happens on some non-alpine systems when running a script in the root of the filesystem.

[tgodzik]

This is interesting, it should not happen since we already check for root. I added additional check in #3131

[lbialy]

Isn't that related to com-lihaoyi/os-lib#276 ?

[tgodzik]

I think this one is different, since we already check for root and return empty string in the case.

[francisdb]

For reference I'm pasting the stack trace we got using the scala 3.5.0 sbt docker build:

root@00eff3a8e8f5:/# scala run test.scala
Error: os.PathError$LastOnEmptyPath: empty path has no last segment
For more details, please see '/.scala-build/stacktraces/1724704787-6633636436291166558.log'
root@00eff3a8e8f5:/# cat /.scala-build/stacktraces/1724704787-6633636436291166558.log
os.PathError$LastOnEmptyPath: empty path has no last segment
  os.PathError$LastOnEmptyPath$.apply(Path.scala:228)
  os.BasePathImpl.last$$anonfun$1(Path.scala:210)
  scala.Option.getOrElse(Option.scala:201)
  os.BasePathImpl.last(Path.scala:210)
  os.BasePathImpl.last$(Path.scala:190)
  os.Path.last(Path.scala:483)
  os.BasePathImpl.baseName(Path.scala:205)
  os.BasePathImpl.baseName$(Path.scala:190)
  os.Path.baseName(Path.scala:483)
  scala.build.input.Inputs$.forValidatedElems(Inputs.scala:155)
  scala.build.input.Inputs$.forNonEmptyArgs(Inputs.scala:415)
  scala.build.input.Inputs$.apply(Inputs.scala:460)
  scala.cli.commands.shared.SharedOptions$.inputs(SharedOptions.scala:692)
  scala.cli.commands.shared.SharedOptions.inputs(SharedOptions.scala:612)
  scala.cli.commands.run.Run$.runCommand(Run.scala:140)
  scala.cli.commands.run.Run$.runCommand(Run.scala:68)
  scala.cli.commands.run.Run$.runCommand(Run.scala:61)
  scala.cli.commands.ScalaCommand.run(ScalaCommand.scala:379)
  scala.cli.commands.ScalaCommand.run(ScalaCommand.scala:361)
  caseapp.core.app.CaseApp.main(CaseApp.scala:157)
  scala.cli.commands.ScalaCommand.main(ScalaCommand.scala:346)
  caseapp.core.app.CommandsEntryPoint.main(CommandsEntryPoint.scala:169)
  scala.cli.ScalaCliCommands.main(ScalaCliCommands.scala:125)
  scala.cli.ScalaCli$.main0(ScalaCli.scala:291)
  scala.cli.ScalaCli$.main(ScalaCli.scala:117)
  scala.cli.ScalaCli.main(ScalaCli.scala)