a novice user trying to run the server on Mac

I modified the paths in lively4S1.sh, install gulp with npm install gulp, and run it, but got this error:

-----------------------------------------
bash-3.2$ bin/lively4S1.sh
LIVELY /Users/ohshima/src/lively4/
SERVER /Users/ohshima/src/lively4/lively4-server/
~/src/lively4 ~/src/lively4
restart http server Fri Apr 20 10:09:02 CEST 2018
~/src/lively4/lively4-server ~/src/lively4 ~/src/lively4
Already up-to-date.
~/src/lively4 ~/src/lively4
~/src/lively4/lively4-server ~/src/lively4 ~/src/lively4
[10:09:07] Using gulpfile ~/src/lively4/lively4-server/gulpfile.js
[10:09:07] Starting 'babel'...
[10:09:08] Finished 'babel' after 1.24 s
~/src/lively4 ~/src/lively4
sed: illegal option -- u
usage: sed script [-Ealn] [-i extension] [file ...]
sed [-Ealn] [-i extension] [-e script] ... [-f script_file] ... [file ...]
sed: illegal option -- u
usage: sed script [-Ealn] [-i extension] [file ...]
sed [-Ealn] [-i extension] [-e script] ... [-f script_file] ... [file ...]
events.js:160
throw er; // Unhandled 'error' event
^

Error: write EPIPE
at exports._errnoException (util.js:1020:11)
at WriteWrap.afterWrite (net.js:800:14)
restart http server Fri Apr 20 10:09:10 CEST 2018
~/src/lively4/lively4-server ~/src/lively4 ~/src/lively4
Already up-to-date.
~/src/lively4 ~/src/lively4
~/src/lively4/lively4-server ~/src/lively4 ~/src/lively4
[10:09:12] Using gulpfile ~/src/lively4/lively4-server/gulpfile.js
[10:09:12] Starting 'babel'...
[10:09:13] Finished 'babel' after 1.24 s
~/src/lively4 ~/src/lively4
sed: illegal option -- u
usage: sed script [-Ealn] [-i extension] [file ...]
sed [-Ealn] [-i extension] [-e script] ... [-f script_file] ... [file ...]
sed: illegal option -- u
usage: sed script [-Ealn] [-i extension] [file ...]
sed [-Ealn] [-i extension] [-e script] ... [-f script_file] ... [file ...]
events.js:160
throw er; // Unhandled 'error' event
^

Start with bin/lively4S1.sh and the server startup path that invokes lively4-server/gulpfile.js, then reproduce the command on macOS and inspect the sed options reported as illegal. Done means the startup script runs without the sed errors or resulting EPIPE and the server starts successfully.

Written by the indexing model from the issue text.