Issue with the build script on FreeBSD during Proftpd installation

[wattie]

I have proftpd enabled and proftpd upload scan enabled. This happens at the end of the build:

/usr/bin/install -c -o ftp -g ftp -m 0644 config.h /usr/local/include/proftpd/config.h
cd include/ && make install
/usr/bin/install -c -o ftp -g ftp -m 0644 proftpd.pc /usr/local/lib/pkgconfig/proftpd.pc
test -z """" || (cd locale/ && make install)
Done proftpd.
./build: unsetenv: not found
Enabling ProFTPd ClamAV module for upload scanning
./build: /usr/bin/prxs: not found
Restarting ProFTPd.
Shutting down proftpd: [ OK ]
Starting proftpd: [ OK ]

In FreeBSD it's /usr/local/bin/prxs. Not sure what's wrong with unsetenv.