Error of 'make clean' for Solaris 11

[email protected]:~/workspace/trunk$ gmake clean
Making clean in upgrades
gmake[1]: Entering directory `/export/home/zabbix/workspace/trunk/upgrades'
gmake[1]: Nothing to be done for `clean'.
...
Making clean in .
gmake[2]: Entering directory `/export/home/zabbix/workspace/trunk/src'
rm -rf libs/zbxcunit/cu_modules.h
for file in `grep "embedded unit tests - remove before commit" * -rl | grep "\.c$"`; do         \
        sed -i /"embedded unit tests - remove before commit"/d $file;   \
done
grep: can't open -rl
gmake[2]: *** [clean-test] Error 1
gmake[2]: Leaving directory `/export/home/zabbix/workspace/trunk/src'
gmake[1]: *** [clean-recursive] Error 1
gmake[1]: Leaving directory `/export/home/zabbix/workspace/trunk/src'
gmake: *** [clean-recursive] Error 1

[email protected]:~/workspace/trunk$ grep -h
Usage: grep [-c|-l|-q] -bhinsvw pattern file . . .