Update the prereq script

[jdemeyer]

1. Added a test for a C99 compiler, since some packages require that.

2. Remove the useless checks for bison and flex (in the past, we did the checks but didn't fail if these programs weren't found).

3. We don't need to check gcc/g++/gfortran versions if we're building GCC. Use the environment variable SAGE_BUILD_TOOLCHAIN (introduced in Add a gcc package #12369) for this.

4. Make the script portable, so it doesn't require bash (instead of use bash for prereq install file #12621, which proposed to force bash).

Apply to the SAGE_ROOT repository:

1. attachment: 12112_from_12576.patch (positive_review, see OS X Lion: don't require setting SAGE_PORT #12576)
2. attachment: 12112_update_prereq.patch

Download http://boxen.math.washington.edu/home/jdemeyer/spkg/prereq-1.0.tar.gz to SAGE_ROOT/spkg/base and delete prereq-0.9.tar.gz (reviewers: look at attachment: prereq-1.0.diff for the changes)

See also: #12785 (update the FAQ)

Depends on #12739
Depends on #12369

Dependencies: #12739, to be merged with #12369

CC: @orlitzky @jhpalmieri @sagetrac-drkirkby

Component: build

Author: John Palmieri, Jeroen Demeyer

Reviewer: Jeroen Demeyer, David Kirkby

Merged: sage-5.0.beta13

Issue created by migration from https://trac.sagemath.org/ticket/12112

[kcrisman]

comment:1

Huh, that would be useful to know for the Cygwin thing as well. Currently we need it there, presumably for the same reason. Thanks.

[orlitzky]

comment:2

Sage may not need it, but the rest of the prereq build system does:

prereq-0.9 $ make
(CDPATH="${ZSH_VERSION+.}:" && cd . && /bin/sh /home/mjo/src/sage-4.8.alpha3/spkg/build/prereq-0.9/missing --run autoheader)
autom4te-2.68: need GNU m4 1.4 or later: /usr/bin/m4
autoheader-2.68: '/usr/bin/autom4te-2.68' failed with exit status: 1
make: *** [config.h.in] Error 1

We could probably ship a pre-built configure and Makefile rather than rely on autotools, but this is black magic to me and I don't understand the tradeoffs involved.

[jdemeyer]

comment:3

Replying to @orlitzky:

Sage may not need it, but the rest of the prereq build system does.

Not really, you just need to run it once, it is sufficient if the developer of the new prereq package runs it before shipping it into Sage.

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1 +1,3 @@
-Since Sage does not need m4, we should not check for it.
+1. Since Sage does not need m4, we should not check for it.
+
+2. We don't need to check gcc/g++/gfortran versions if we're building GCC.

[jdemeyer]

Dependencies: #12739

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1,3 +1,7 @@
 1. Since Sage does not need m4, we should not check for it.
 
 2. We don't need to check gcc/g++/gfortran versions if we're building GCC.
+
+**Apply** to the SAGE_ROOT repository:
+1. [attachment: 12112_from_12576.patch](https://github.com/sagemath/sage-prod/files/10654145/12112_from_12576.patch.gz) (**positive_review**, see #12576)
+2. [attachment: 12112_update_prereq.patch](https://github.com/sagemath/sage-prod/files/10654146/12112_update_prereq.patch.gz)

[jdemeyer]

Reviewer: Jeroen Demeyer

[jdemeyer]

Changed author from Jeroen Demeyer to John Palmieri, Jeroen Demeyer

[jdemeyer]

Attachment: 12112_from_12576.patch.gz