=> "/opt/pkg/bin/bmake" ["-C", "/data/jenkins/workspace/pkgsrc-upstream-trunk/archivers/lz4json", "all", "BATCH=1", "DEPENDS_TARGET=/nonexistent"]
===> Building for lz4json-0.0.20191229
cd /home/pbulk/work/archivers/lz4json/work/lz4json-c44c51005c505de2636cc1e59cde764490de7632 && gcc  -pipe -O2 -msave-args -fno-aggressive-loop-optimizations  -I/opt/pkg/include  -L/opt/pkg/lib -Wl,-R/opt/pkg/lib lz4jsoncat.c -o lz4jsoncat `pkg-config --libs liblz4` `pkg-config --cflags liblz4`
lz4jsoncat.c: In function 'main':
lz4jsoncat.c:42:26: error: implicit declaration of function 'open'; did you mean 'popen'? [-Wimplicit-function-declaration]
   42 |                 int fd = open(*av, O_RDONLY);
      |                          ^~~~
      |                          popen
*** Error code 1

Stop.
bmake[1]: stopped making "all" in /data/jenkins/workspace/pkgsrc-upstream-trunk/archivers/lz4json
*** Error code 1

Stop.
bmake: stopped making "all" in /data/jenkins/workspace/pkgsrc-upstream-trunk/archivers/lz4json