Re: which shell is running configure?

[Sam Steingold]

> * Eric Blake <address@hidden> [2006-06-28 06:10:35 -0600]:
>
> According to Sam Steingold on 6/27/2006 10:17 AM:
>> I encountered the following problem:
>> an autoconf test that checks whether `test' supports `-nt' passes,
>> but when make tries to use "test -nt" in Makefile, it fails.
>> this appeared to suggest that configure and make were using different
>> shells, and, indeed, I found some code in configure which appears to
>> re-run it with bash:
> ...
>>
>> why is this being done?
>
> You are correct that configure reruns itself with a better shell, if
> the default is insufficient for its needs, and CONFIG_SHELL was not
> set (setting CONFIG_SHELL is useful in part as a torture test of
> autoconf being able to work in spite of insufficient shells, but also
> so that you can manually choose a better shell rather than wasting
> configure's time finding it).  Does adding something like
> address@hidden@ to Makefile.in help your situation?

of course not - configure and config.status do not substitute @address@hidden

moreover, I inserted the following into the configure by hand:

echo SHELL=${SHELL}
echo CONFIG_SHELL=${CONFIG_SHELL}
echo 0=$0
echo BASH_VERSION=${BASH_VERSION}
echo BASH=${BASH}

here is what was printed:

SHELL=/bin/sh
CONFIG_SHELL=
0=configure
BASH_VERSION=2.05.0(1)-release
BASH=/bin/bash

so, obviously the configure script is being run by bash, but neither
SHELL nor CONFIG_SHELL tell me that, so when I put
SHELL=${CONFIG_SHELL-${SHELL-/bin/sh}}
into the generated shell script (that writes Makefile),
Makefile gets

SHELL = /bin/sh

which causes the original problem.


> The autoconf manual discusses the use of CONFIG_SHELL.

all I can find is this:

 - Variable: CONFIG_SHELL
     The shell with which to run `configure' for the `--recheck'
     option.  It must be Bourne-compatible.  The default is a shell that
     supports `LINENO' if available, and `/bin/sh' otherwise.

-- 
Sam Steingold (http://www.podval.org/~sds) on Fedora Core release 5 (Bordeaux)
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