When running the configure script on Solaris SPARC (versions 10 and 11), the script fails with the following error:

    checking whether float word ordering is bigendian... unknown
    configure: error:

    Unknown float word ordering. You need to manually preset
    ax_cv_c_float_words_bigendian=no (or yes) according to your system.


The configure script uses "grep" on a compiled binary to see how a float variable is compiled. On Solaris, the regular "grep" command may be an old version that fails to search in a binary file. The correct command should be "ggrep" (the GNU grep).
Luckily, Python's configure script already finds this command in an earlier check:

    checking for grep that handles long lines and -e... /usr/bin/ggrep

All we have to do, then, is use the command that configure finds. i.e. replace "grep" -> "$GREP".