Arch Linux

downloading arduino-1.8.9-linux64.tar.xz from the arduino site and installing with included scrips resolved. had to delete ~/.arduino and scripts did complain, but it works.

I had the same problem, it's not specific to the esp8266.
Downgrading solved it:
pacman -U /var/cache/pacman/pkg/arduino-1\:1.8.9-1-x86_64.pkg.tar.xz

Same problem here: arduino 1:1.8.9-3

Cannot be fixed in arduino 1:1.8.9-4?

Same problem here: arduino 1:1.8.9-3

Cannot be fixed in arduino 1:1.8.9-4?

Can confirm problem. Was fixed by downgrading to previous version. Sketch does not
matter... just by opening the tools/serial monitor will cause the issue.
last known working version:
sudo pacman -U /var/cache/pacman/pkg/arduino-1:1.8.9-2-x86_64.pkg.tar.xz

I have the following java related packages installed:
jre8-openjdk 8.u212-1
jre8-openjdk-headless 8.u212-1

tried installing (jre-openjdk and jre-openjdk-headless to get latest versions)
jre-openjdk 11.0.3.u4-1
jre-openjdk-headless 11.0.3.u4-1

even after a restart, the exception still exists when opening the serial monitor window.

SUCCESS!
had to remove jre8-openjdk and jre8-openjdk-headless and install the latest
jre-openjdk and jre-openjdk-headless packages. This updated to version 11 of jdk
and the serial monitor is now running without complaints.

Uninstalling jre8-openjdk and jre8-openjdk-headless isn't an option for me, because other software depends on it. So for me this issue isn't fixed.

@sekret

It should be noted that you can switch between multiple Java versions without uninstalling the old version. That's what the `archlinux-java` utility is for. If I'm not mistaken, what it actually does is change the `/usr/lib/jvm/default-runtime` symlink to point to one of the various Java installations. All packages that are for the various runtime versions should show up under `pacman -Ss jre` -- you can install as many different versions as you want. The wiki goes into more detail on this: https://wiki.archlinux.org/index.php/Java#Switching_between_JVM

If whatever you're using requires that jre8 to be default runtime, here is a workaround:

If you look in `/usr/bin/arduino` you'll find a wrapper shell script that is hardcoded to set the default directory. If you copy that wrapper to `/usr/local/bin/arduino` and then edit it, you should be able to override the PATH set in the wrapper to the desired runtime -- thus making Arduino use one Java version while the rest of the system uses another.

It's kind of an ugly approach, but it's all I could think of off the top of my head. If anyone knows anything better let me know. (Also, if this really is the best way, maybe someone should open an issue with the packager for the `arduino` package -- ask them to create a wrapper script that allows you to set this via environment variables.

On a side note, when I use JRE11 with the Arduino IDE, it gives my compilation console a grey background (despite it still being white-on-black text) and seems to break quite a lot of other parts of the GUI (such as the boarders of check boxes missing). Is this a bug or just some really badly designed theme? Anyone know a fix? (Am using pretty standard Xorg & XFCE4 setup with Intel graphics card, BTW.)

Edit: I tried using JRE10, and it fixed the GUI -- and fixed the error message too. Interesting.

I'd like to suggest changing depends from java-runtime>=8:

depends=('gtk2' 'desktop-file-utils' 'shared-mime-info' 'java-runtime>=8' 'arduino-builder')

to java-runtime>=10

depends=('gtk2' 'desktop-file-utils' 'shared-mime-info' 'java-runtime>=10' 'arduino-builder')

On a post to the Arduino forum, https://forum.arduino.cc/index.php?topic=621098.msg4208185#msg4208185, I got pointed to the corresponding bug in Arduino on github, https://github.com/arduino/Arduino/issues/8903, and dug a little deeper. Instead of using the system installed version of Java 10 or 11 as I suggested above, https://bugs.archlinux.org/task/62704#comment179725. I now think it would be better to use the Java shipped with released version of arduino was suggested on the github issue, https://github.com/arduino/Arduino/issues/8903#issuecomment-497702534.

The reason is that even though using java 10 or 11 resolves this particular issue I get warnings when I use them:

$ archlinux-java status
Available Java environments:
java-10-openjdk (default)
java-11-openjdk
java-8-openjdk

$ /usr/share/arduino/arduino
Picked up JAVA_TOOL_OPTIONS:
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by processing.app.linux.GTKLookAndFeelFixer (file:/usr/share/arduino/lib/arduino-core.jar) to field com.sun.java.swing.plaf.gtk.GTKLookAndFeel.styleFactory
WARNING: Please consider reporting this to the maintainers of processing.app.linux.GTKLookAndFeelFixer
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

This doesn't happen when using the Java 8 shipped with arduino-1.8.9:

$ /home/wink/bin/arduino-1.8.9/java/bin/java -version
java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)

Which you can see is different from Arch Linux Java 8:

$ archlinux-java status
Available Java environments:
java-10-openjdk
java-11-openjdk
java-8-openjdk (default)

$ /usr/bin/java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (build 1.8.0_212-b01)
OpenJDK 64-Bit Server VM (build 25.212-b01, mixed mode)

If what Wink says is accurate, I don't think removing Java 8 and upgrading to Java 10 is the correct fix. The package should probably use the shipped Java version that comes with arduino.

Also the package arduino-1:1.8.9-2-x86_64.pkg.tar.xz works fine on my machine, while arduino-1:1.8.9-3-x86_64.pkg.tar.xz has the problem with the serial monitor. Perhaps identify what changed between the two packages.

I can confirm the statement of Wink. I also get those warnings if I switch to the newer java version.

Any word on a fix for this bug? As of Arduino-1.8.12 it is still apparent.
Arduino-1.8.9-2 works but nothing higher.

Exception in thread "EventThread /dev/ttyUSB0" java.lang.NoSuchMethodError: java.nio.ByteBuffer.flip()Ljava/nio/ByteBuffer;
is still the error displayed when trying to use the serial monitor.

Same problem here (arduino 1.8.12)

$ java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (build 1.8.0_242-b08)
OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)

Not present with Nano & old bootloader, but present with (new) bootloader

This appears to be fixed upstream as of yesterday. https://github.com/arduino/Arduino/issues/10187

A new arduino version was released. For me it seems to work with java14, can anyone please verify?

Cant confirm that. Problem occurs with arduino 1:1.8.13-2 and jre-openjdk 14.0.2.u12-1

Confirming this bug seems solved to me on

openjdk version "14.0.2" 2020-07-14
OpenJDK Runtime Environment (build 14.0.2+12)
OpenJDK 64-Bit Server VM (build 14.0.2+12, mixed mode)

with Arduino 1.8.13

The bug is actually this, and it hasn't been fixed yet
https://github.com/arduino/Arduino/issues/8903

Maybe the java-runtime depend should be made >8 or something like that?

Problem is the wrapper script `/usr/bin/arduino` because it uses *default-runtime*. And if arduino is not build with jdk8 it does not run with jdk8 because of an incompatible change in jdk9: `ByteBuffer.flip()` returns `ByteBuffer` instead of `Buffer`.

So to fix this as a user choose a default jdk >= 8 and to fix the package make the jdk that is used to build the package a dependency and use the versioned path instead of the default.

Thanks for this important hint! So the best solution is to build with java 14 and also depend/run on java 14? Or would it also run with 11, but not with 8?

It seems to only work properly with java8, so I stick to that for now.