Re: Requiring Bourne shell for build

[John W. Eaton]

On 02/17/2016 12:56 PM, Mike Miller wrote:
> On Wed, Feb 17, 2016 at 09:45:41 -0800, Rik wrote:
> > 2/17/16
> >
> > Mike,
> >
> > I see that you recently added some changesets that add $(SHELL) to the
> > invocation of most scripts.  In theory, this seems appropriate because it
> > allows the user to override SHELL with their own tool.  In practice,
> > however, the build is keyed to using Bourne shell.  I happen to use tcsh so
> > SHELL is /bin/tcsh.  This is an exported environment variable so even if I
> > drop into sh first before trying to run the build system I get errors.  I
> > can get the build to work by doing
> >
> > sh
> > SHELL=/bin/sh
> > export SHELL
> > bootstrap
> > configure
> > make
> > exit
> >
> > It seems that instead of making the build platform SHELL agnostic, it is
> > now required to use /bin/sh for all operations.
>
> Thanks for pointing that out. I thought there might be a csh
> complication somewhere, thanks for being the guinea pig. If only
> everyone could use a POSIX shell ;)
>
> Just reading this relevant section of the GNU make manual:
>
> https://www.gnu.org/software/make/manual/make.html#Choosing-the-Shell
>
> Most of these might start working for you if you add an "export SHELL"
> to build-aux/common.mk alongside the other exports. But that wouldn't
> fix the changes to bootstrap.
>
> I'd like to get away with keeping most of the changes, maybe only revert
> 41e39c9b35d3.

What about using something like

  SHELL=${CONFIG_SHELL-/bin/sh}

in the bootstrap script (see the attached diff)?  I don't think we need 
to do as much to try to set SHELL (or CONFIG_SHELL) as the 
autoconf-generated configure script does, but this should fix the 
problem with getting a bad value for SHELL from the environment while 
still allowing users to choose what (POSIX) shell to use for running the 
Octave scripts that are executed by the bootstrap script.

I also see that autoconf sets the variable with '-' and you used ':-'. 
Either is OK with me, but I wonder if there is a reason that autoconf 
only uses the default if CONFIG_SHELL is unset, not also if it is null.

In any case, if I make this change, then I don't see a problem when 
doing the following with a clean build tree:

  export SHELL=/bin/tcsh
  ./bootstrap              ## in source tree
  /path/to/configure       ## in build tree
  make

jwe

diffs.txt
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