"phing" executable is in the $PATH, but it cannot be executed by the phing plugin, which doesn't find the executable

Here is the output with the default config:

[ci-mypartner-env-production] $ /bin/sh -xe /tmp/hudson7958496970301516477.sh
+ echo PATH
PATH
+ echo /usr/kerberos/bin:/usr/local/zend/bin:/usr/local/bin:/bin:/usr/bin
/usr/kerberos/bin:/usr/local/zend/bin:/usr/local/bin:/bin:/usr/bin
+ which phing
/usr/local/zend/bin/phing
looking for '/var/lib/jenkins/workspace/project/utils/build/build.xml' ...
use '/var/lib/jenkins/workspace/project' as a working directory.
[project] $ phing -buildfile /var/lib/jenkins/workspace/project/utils/build/build.xml -logger phing.listener.DefaultLogger
FATAL: command execution failed.Maybe you need to configure the job to choose one of your Phing installations?
java.io.IOException: Cannot run program "phing" (in directory "/var/lib/jenkins/workspace/project"): java.io.IOException: error=2, No such file or directory

If i create a specific phing config, then the command launched is:

php -buildfile /var/lib/jenkins/workspace/project/utils/build/build.xml -logger phing.listener.DefaultLogger

where the expected command should be

phing -buildfile /var/lib/jenkins/workspace/project/utils/build/build.xml -logger phing.listener.DefaultLogger