JLine error when attempting to run the REPL with piped input

[deanwampler]

Scala 3.0.0-RC2. A command like the following:

$ scala <<EOF
:load somestuff.scala
EOF

or trying:

$ echo ":load src/script/scala/progscala3/hierarchy/Asserts.scala" | scala

Both cause this exception:

Exception in thread "main" java.lang.IllegalStateException: Unable to create a system terminal
	at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:323)
	at org.jline.terminal.TerminalBuilder.build(TerminalBuilder.java:265)
	at dotty.tools.repl.JLineTerminal.<init>(JLineTerminal.scala:23)
	at dotty.tools.repl.ReplDriver.runUntilQuit(ReplDriver.scala:123)
	at dotty.tools.repl.ReplDriver.tryRunning(ReplDriver.scala:114)
	at dotty.tools.repl.Main$.main(Main.scala:6)
	at dotty.tools.repl.Main.main(Main.scala)

This is fairly well known issue, see for example https://youtrack.jetbrains.com/issue/IDEA-183619. I attempted to use the recommended fix, setting the property -Dorg.jline.terminal.dumb=true. I did this by passing the argument -J-Dorg.jline.terminal.dumb=true to the REPL, even though this argument is not documented for the REPL in the -help output. It appeared to be ignored or do nothing. I also tried setting the environment variable JAVA_OPTS=-Dorg.jline.terminal.dumb=true before starting the REPL, but that didn't work either. Finally, I even tried setting the property inside the REPL, i.e.,

$ scala <<EOF
System.setProperty("...", "...")
:load somestuff.scala
EOF

I would expect this to be too late. It also doesn't help.

Note that in the Scala 2.13 REPL, without setting the property, you get a warning that it will default to a dumb terminal, but otherwise appears to work fine.

[griggt]

These incantations using TERM=dumb seem to work (at least on Linux)

$ TERM=dumb scala <<EOF
:load somestuff.scala
EOF

$ echo ":load src/script/scala/progscala3/hierarchy/Asserts.scala" | TERM=dumb scala

But we should probably gracefully fall back to a dumb terminal like Scala 2 does, as was also suggested here.

[deanwampler]

I just noticed in #11707 that using TERM=dumb should work. I confirmed it works on MacOS, too, just now. Thanks!

[catap]

Interesting that without TERM=dumb it simple doesn't work on OpenBSD

[catap]

#19744 may fixe this

[Gedochao]

Sadly, this is still broken, even on the new scala runner / Scala CLI.

echo 'object Example { def smth = "smth" }' |scala-cli repl _   
# Compiling project (Scala 3.4.2, JVM (17))
# Compiled project (Scala 3.4.2, JVM (17))
# Exception in thread "main" java.lang.IllegalStateException: Unable to create a terminal
# 	at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:394)
# 	at org.jline.terminal.TerminalBuilder.build(TerminalBuilder.java:362)
# 	at dotty.tools.repl.JLineTerminal.<init>(JLineTerminal.scala:25)
# 	at dotty.tools.repl.ReplDriver.runUntilQuit(ReplDriver.scala:145)
# 	at dotty.tools.repl.ReplDriver.tryRunning(ReplDriver.scala:136)
# 	at dotty.tools.repl.Main$.main(Main.scala:7)
# 	at dotty.tools.repl.Main.main(Main.scala)
# 	Suppressed: java.io.IOException: Unable to find terminal provider ffm
# 		at org.jline.terminal.spi.TerminalProvider.load(TerminalProvider.java:74)
# 		at org.jline.terminal.TerminalBuilder.checkProvider(TerminalBuilder.java:667)
# 		at org.jline.terminal.TerminalBuilder.getProviders(TerminalBuilder.java:632)
# 		at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:395)
# 		... 6 more
# 	Suppressed: java.io.IOException: Unable to find terminal provider jni
# 		at org.jline.terminal.spi.TerminalProvider.load(TerminalProvider.java:74)
# 		at org.jline.terminal.TerminalBuilder.checkProvider(TerminalBuilder.java:667)
# 		at org.jline.terminal.TerminalBuilder.getProviders(TerminalBuilder.java:634)
# 		at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:395)
# 		... 6 more
# 	Suppressed: java.io.IOException: Unable to find terminal provider jansi
# 		at org.jline.terminal.spi.TerminalProvider.load(TerminalProvider.java:74)
# 		at org.jline.terminal.TerminalBuilder.checkProvider(TerminalBuilder.java:667)
# 		at org.jline.terminal.TerminalBuilder.getProviders(TerminalBuilder.java:636)
# 		at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:395)
# 		... 6 more
# 	Suppressed: java.io.IOException: Unable to load terminal provider jna: null
# 		at org.jline.terminal.spi.TerminalProvider.load(TerminalProvider.java:71)
# 		at org.jline.terminal.TerminalBuilder.checkProvider(TerminalBuilder.java:667)
# 		at org.jline.terminal.TerminalBuilder.getProviders(TerminalBuilder.java:638)
# 		at org.jline.terminal.TerminalBuilder.doBuild(TerminalBuilder.java:395)
# 		... 6 more
# 	Caused by: java.lang.reflect.InvocationTargetException
# 		at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
# 		at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
# 		at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
# 		at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
# 		at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
# 		at org.jline.terminal.spi.TerminalProvider.load(TerminalProvider.java:69)
# 		... 9 more
# 	Caused by: java.lang.UnsupportedOperationException: Unsupported platform mac-aarch64
# 		at org.jline.terminal.impl.jna.JnaNativePty.isatty(JnaNativePty.java:194)
# 		at org.jline.terminal.impl.jna.JnaNativePty.isPosixSystemStream(JnaNativePty.java:170)
# 		at org.jline.terminal.impl.jna.JnaTerminalProvider.checkSystemStream(JnaTerminalProvider.java:124)
# 		at org.jline.terminal.impl.jna.JnaTerminalProvider.<init>(JnaTerminalProvider.java:31)
# 		... 15 more

[mbovel]

Reading #11707 it seems to me that the right thing to do here might just be to keep the default value of dump to null instead of setting it to false when the dump terminal is not forced. This would allow JLine to fall back to a dump terminal if needed.