=> Bootstrap dependency digest>=20010302: found digest-20190127
=> Checksum SHA1 OK for gsl-2.1.0.3.gem
=> Checksum RMD160 OK for gsl-2.1.0.3.gem
=> Checksum SHA512 OK for gsl-2.1.0.3.gem
===> Installing dependencies for ruby25-gsl-2.1.0.3
=> Build dependency cwrappers>=20150314: found cwrappers-20180325
=> Full dependency ruby25-base>=2.5.9: NOT found
=> Verifying /nonexistent for ../../lang/ruby25-base
make[1]: don't know how to make /nonexistent. Stop

make[1]: stopped in /usr/pkgsrc/lang/ruby25-base
*** Error code 2

Stop.
make: stopped in /usr/pkgsrc/math/ruby-gsl