Read-only file system when trying to set new build.path on Mac

[lj001]

I wanted to move my build directory on my Mac and found these instructions, which I followed.

Arduino compiler output location on a Mac? - Using Arduino / Programming Questions - Arduino Forum

Which said to edit the preferences.txt to include:

build.path=~/Documents/Arduino/build

But I am getting an error now when I try to compile:

java.nio.file.FileSystemException: /~: Read-only file system
	at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
	at sun.nio.fs.UnixFileSystemProvider.createDirectory(UnixFileSystemProvider.java:384)
	at java.nio.file.Files.createDirectory(Files.java:674)
	at java.nio.file.Files.createAndCheckIsDirectory(Files.java:781)
	at java.nio.file.Files.createDirectories(Files.java:767)
	at processing.app.Sketch.getBuildPath(Sketch.java:183)
	at cc.arduino.Compiler.build(Compiler.java:163)
	at processing.app.SketchController.build(SketchController.java:664)
	at processing.app.Editor$BuildHandler.run(Editor.java:1632)
	at java.lang.Thread.run(Thread.java:748)
/~: Read-only file system

but when I run ls -l I get drwxr-xr-x on the directory.

I also read this article Arduino Preferences | Arduino Documentation | Arduino Documentation

[J-M-L]

@lj001

I wanted to move my build directory on my Mac

what do you mean by that and what did you do exactly?

[ptillisch]

Hi @lj001. The problem is your use of the ~ path alias in the property. This is something your shell knows about, which is why it works with a command like ls -l ~/Documents/Arduino/build, but Arduino IDE doesn't know anything about the alias so it is treating this as if it is a literal path.

The solution is to replace the ~ in the property value with the true path:

build.path=/Users/<user name>/Documents/Arduino/build

(replace <user name> in the text above with your macOS user name)

[lj001]

That worked. Thank you.

[ptillisch]

You are welcome. I'm glad it is working now.

Regards,
Per