I'm installin Python 3.91. on a Solaris 10 system (I known it's 'old' but I have a legacy installation to support).

Running ./configure the following errors are seen...

checking PROFILE_TASK... -m test --pgo
checking for --with-lto... no
checking for llvm-profdata... no
grep: illegal option -- q
Usage: grep -hblcnsviw pattern file . . .
checking for -Wextra... yes
checking whether /usr/sfw/bin/gcc accepts and needs -fno-strict-aliasing... yes
checking if we can turn off /usr/sfw/bin/gcc unused result warning... no
checking if we can turn off /usr/sfw/bin/gcc unused parameter warning... yes


and


checking aligned memory access is required... yes
checking for --with-hash-algorithm... default
checking for --with-tzpath... grep: illegal option -- q
grep: illegal option -- E
Usage: grep -hblcnsviw pattern file . . .
"/usr/share/zoneinfo:/usr/lib/zoneinfo:/usr/share/lib/zoneinfo:/etc/zoneinfo"
checking for --with-address-sanitizer... no
checking for --with-memory-sanitizer... no
checking for --with-undefined-behavior-sanitizer... no
checking for t_open in -lnsl... yes
checking for socket in -lsocket... yes