Make error: multiple target patterns. Stop

[ProodjePindakaas]

When trying to build anything, the make procedure will result in the following error similar to #174:
makefile:153: *** multiple target patterns. Stop.

After looking at the respective line in the makefile I found that APP_LIBNNP (and the variables at line 154 and 155) is defined as the string

make[1]: Entering directory '[....]/n2p2/src/application' nnp-convert nnp-cutoff nnp-dist nnp-predict nnp-prune nnp-select nnp-symfunc make[1]: Leaving directroy '[...]/n2p2/src/application'

Running the makefile with supression of other makefile output as make -s results in normal behavior, however this should not be needed for a normal build procedure.

Additional info:
commit: 539576b
make version: GNU Make 4.4.1