There's no functional impact, but the error message is confusing.

When a new mobile hybrid engine is configured, this error is logged:

!ENTRY org.eclipse.thym.android.core 2 0 2015-04-28 14:38:54.071
!MESSAGE Missing Android engine file /home/ldimaggi/.cordova/lib/android/cordova/3.7.1/framework/cordova-3.7.1.jar

The file, however, is right where it belongs:

ll /home/ldimaggi/.cordova/lib/android/cordova/3.7.1/framework/cordova-3.7.1.jar
rw-rw-r-. 1 ldimaggi ldimaggi 357355 Apr 28 14:38 /home/ldimaggi/.cordova/lib/android/cordova/3.7.1/framework/cordova-3.7.1.jar