On Tue, Mar 9, 2021 at 5:00 PM Tim Rice <tim@xxxxxxxxxxxxxxxx> wrote: > On Tue, 9 Mar 2021, Warren Young wrote: > > On Mar 9, 2021, at 1:26 PM, Paul Eggert <eggert@xxxxxxxxxxx> wrote: > > Solaris 10 dates from early 2005. We gave it 16 years of direct support, and now it’s on a sort of “extended” support if you point Autoconf configure scripts at a reasonable shell. > > The thing is, it is not even necessary to point Autoconf configure > scripts at a reasonable shell. The configure script will find a capable > shell and run itself with that shell. > > UnixWare has a /bin/sh as crufty as Solaris 10. I just pulled the > latest config.guess and config.sub into my OpenSSH tree and configure > was just as happy as before. Like Solaris /bin/sh, UniWare's does > not handle $(...) either. N.B. I changed Autoconf's "find us a better shell" logic in 2.70 to include checking for $(...) _specifically because of_ the change being debated here. Configure scripts themselves still use `...` nigh-exclusively. I don't want to either tear down or defend Ben's change, but it's my personal opinion that use of $(...) is a lot more defensible in a configure script than in config.{sub,guess}, because it _has_ that "find a better shell" step at the beginning. Also, configure would get more out of being able to use $(...) than config.{sub,guess} do, just because its code is typically more complicated, and configure scripts tend to pull in third-party code from all over the place that may or may not ever have been tested on anything old. For these reasons I probably wouldn't revert the Autoconf change even if the config.{sub,guess} change were reverted. zw