=> Bootstrap dependency digest>=20211023: found digest-20220214
=> Checksum BLAKE2s OK for libbpg-0.9.2.tar.gz
=> Checksum SHA512 OK for libbpg-0.9.2.tar.gz
===> Installing dependencies for libbpg-0.9.2
==========================================================================
The following variables will affect the build process of this package,
libbpg-0.9.2.  Their current value is shown below:

        * JPEG_DEFAULT = jpeg

Based on these variables, the following variables have been set:

        * JPEGBASE (defined, but empty)
        * JPEG_TYPE = jpeg

You may want to abort the process now with CTRL-C and change the value
of variables in the first group before continuing.  Be sure to run
`/usr/bin/make clean' after the changes.
==========================================================================
=> Tool dependency mktools-[0-9]*: found mktools-20220614
=> Tool dependency gmake>=3.81: found gmake-4.4.1
=> Tool dependency cwrappers>=20150314: found cwrappers-20220403
=> Full dependency png>=1.6.0nb1: NOT found
=> Verifying /nonexistent for ../../graphics/png
make[1]: don't know how to make /nonexistent. Stop

make[1]: stopped in /usr/pkgsrc/graphics/png
*** Error code 2

Stop.
make: stopped in /usr/pkgsrc/graphics/libbpg