Why does Maven use the wrong JDK version when running from Fish?

I run macOS Sierra, and have installed the Fish shell (https://fishshell.com/).

When I try to build a Maven project, it now gives me

Fatal error compiling: invalid target release: 1.8 ->

... which means that it has picked up an older JDK which it tries to use to build my Java 8 project with.

This is made obvious by running mvn -version:

...
Java version: 1.6.0_65, vendor: Apple Inc.
Java home: /Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
...

But I have JAVA_HOME set correctly, echo $JAVA_HOME in both shells give me:

/Library/Java/JavaVirtualMachines/jdk1.8.0_112.jdk/Contents/Home

and java -version gives me

java version "1.8.0_112"
Java(TM) SE Runtime Environment (build 1.8.0_112-b16)

and javac -version:

javac 1.8.0_112

echo $PATHgives the same result in both shells (except that in Bash, the directories are separated by :; in Fish, a space ):

/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Applications/Server.app/Contents/ServerRoot/usr/bin:/Applications/Server.app/Contents/ServerRoot/usr/sbin

I have configured maven-compiler-plugin to for 1.8:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.6.0</version>
  <configuration>
    <source>1.8</source>
    <target>1.8</target>
    <encoding>${project.build.sourceEncoding}</encoding>
  </configuration>
</plugin>

Why does Maven insist on using the 1.6 JDK? The same project builds fine, with the correct 1.8 JDK, when running through Bash.

Solution

If you are running an old version of maven, please try updating to the latest version (3.5.0), e.g. via homebrew (brew install maven).