On Mon, 8 Mar 2021, Nick Bowler wrote: > Hi, > > I noticed that config.sub (and config.guess) scripts were very recently > changed to use the POSIX $(...) form for command substitutions. > > This change is, I fear, ill-advised. The POSIX construction is > widely understood to be nonportable as it is not supported by > traditional Bourne shells such as, for example, Solaris 10 /bin/sh. > This specific portability problem is discussed in the Autoconf manual > for portable shell programming[1]. > > These scripts using $(...) are incorporated into the recently-released > Automake 1.16.3, which means they get copied into packages bootstrapped > with this version. So now, if I create a package using the latest bits, > configuring with heirloom-sh fails: > > % CONFIG_SHELL=/bin/jsh jsh ./configure CONFIG_SHELL=/bin/jsh > configure: error: cannot run /bin/jsh ./config.sub But why would you use CONFIG_SHELL= to specify a less capable shell? It is there to specify a more capable shell in case it is not already detected. Now if an autoconf built configure attempts to run config.guess/config.sub before detecting a capapable shell and exec(ing) itself, then that is not so good. > % jsh config.sub x86_64-pc-linux-gnu > config.sub: syntax error at line 53: `me=$' unexpected > > (The heirloom-sh is essentially Solaris /bin/sh but runs on GNU/Linux systems). -- Tim Rice Multitalents tim@xxxxxxxxxxxxxxxx
