[jerome@jeroboam] > make
clang -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument -D_XOPEN_SOURCE -I. -I./ -I/usr/local/Cellar/postgresql@9.4/9.4.18/include/server -I/usr/local/Cellar/postgresql@9.4/9.4.18/include/internal -I/usr/local/opt/openssl/include -I/usr/local/opt/readline/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.13.sdk/usr/include/libxml2 -c -o src/pg_proctab.o src/pg_proctab.c
src/pg_proctab.c:14:10: fatal error: 'sys/vfs.h' file not found
#include
^~~~~~~~~~~
1 error generated.
make: *** [src/pg_proctab.o] Error 1
Then replace
#include <sys/vfs.h>
with
#if defined(__APPLE__)
#include <sys/mount.h>
#else
#include <sys/vfs.h>
#endif
