use bash for prereq install file

[jhpalmieri]

The script prereq-0.9-install starts with the line

#!/bin/sh

As a result, when installing prereq on a Solaris machine, I see this:

Starting prerequisite check.
Machine: SunOS mark2 5.10 Generic_127111-01 sun4u sparc SUNW,Sun-Blade-2500
base/prereq-0.9-install: !: not found
checking for a BSD-compatible install... ./install-sh -c

I think this is because of the line

if ! [ -f "$SAGE_ROOT/spkg/base/$TARGET.tar" ]; then

in prereq-0.9-install. Using bash to run this script instead of sh fixes the problem. So I propose using bash for this script.

This will be fixed in #12112.

Depends on #4949

Component: build

Reviewer: Jeroen Demeyer

Issue created by migration from https://trac.sagemath.org/ticket/12621

[jhpalmieri]

Attachment: trac_12621-prereq.patch.gz

[jhpalmieri]

Dependencies: #4949

[jhpalmieri]

comment:2

Attachment: trac_12621-prereq.v2.patch.gz

[jdemeyer]

Reviewer: Jeroen Demeyer