Builds work for me on Solaris 10 sparc, but then I don't have a
locally-installed /usr/local/bin/grep to get in the way and cause trouble. I
suggest removing /usr/local/bin from your PATH, or setting the GREP environment
variable to be the 'grep' you prefer.
I used PATH='/usr/bin:/usr/ccs/bin:/r/share1/src/developerstudio12.6/bin' in my
build, and got this:
checking for grep that handles long lines and -e... /usr/xpg4/bin/grep
checking for egrep... /usr/xpg4/bin/grep -E
It is true that you need a working 'grep' to build GNU grep, just as you need a
working 'cp' to build GNU cp. The GNU coding standards allow builds to depend on
a small set of POSIX tools, and 'grep' and 'cp' are both on the list.