This post describes a fix of the .onLoad failed in loadNamespace() for 'rJava' error, which occurs when loading rJava in RStudio using macOS. Credit for this fix goes to Toontje.

The ‘2015’ fix stopped working

In beginning of 2015 I wrote a blog post that shows you how to run rJava in RStudio using OSX 10.10. The fix stopped working. Toontje, a reader of my blog, came for the rescue.

The workaround was tested using the following software:

• R 3.3.2
• RStudio 1.0.136
• macOS 10.12.3 (16D32)
• jdk 1.8.0_112
• rJava 0.9-8

Loading rJava yields “.onload failed … for rJava” error

I installed rJava using install.packages('rJava') without errors. Loading the library in an R session launched in the terminal works. Loading rJava in RStudio yields the following error:

library('rJava')
Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: unable to load shared object '/Users/paul/Desktop/rJava_test/packrat/lib/x86_64-apple-darwin15.6.0/3.3.2/rJava/libs/rJava.so':
  dlopen(/Users/paul/Desktop/rJava_test/packrat/lib/x86_64-apple-darwin15.6.0/3.3.2/rJava/libs/rJava.so, 6): Library not loaded: @rpath/libjvm.dylib
  Referenced from: /Users/paul/Desktop/rJava_test/packrat/lib/x86_64-apple-darwin15.6.0/3.3.2/rJava/libs/rJava.so
  Reason: image not found
Error: package or namespace load failed for ‘rJava’

Use “dyn.load(<your_jre_path>)” to fix the problem

Launching RStudio using a custom call specifying the jre library doesn’t work anymore. In the new approach we will load it directly to the running R session.

Check if everything works as expected

At first we check if everything else works as expected.

# `which java` should yield something like this: `/usr/bin/java`
$ which java
/usr/bin/java
# `/usr/libexec/java_home` should yield the current jdk home folder
$ /usr/libexec/java_home
/Library/Java/JavaVirtualMachines/jdk1.8.0_31.jdk/Contents/Home

You can also use /usr/libexec/java_home to switch your java version if you wish. You can download the newest jre from the Oracle here.

If the output is similar to the one above you should be fine!

Run “dyn.load(<your_jre_path>)” in RStudio

Open a new RStudio session. Now, load the jre library using the command:

dyn.load(paste0(system2('/usr/libexec/java_home', stdout = TRUE), '/jre/lib/server/libjvm.dylib'))

This command executes /usr/libexec/java_home and concatinates the stdout to the library path /jre/lib/server/libjvm.dylib.

That’s it. Now you should be able to load library(rJava) without errors.