remove SAGE_INSTALL_GCC variable

[dimpase]

I think with the latest —with-system-* options, it can and should be removed as superseded.

The branch here updated docs to make SAGE_INSTALL_GCC obsolete and
removed it everywhere, except one place. Alternative means to use
system compilers are explained.

The actual removal from the code will be done in a follow-up ticket.

CC: @kiwifb @embray @jdemeyer @mkoeppe @nthiery

Component: documentation

Author: Dima Pasechnik

Branch/Commit: a9c8ddd

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/27817

[embray]

comment:1

I think so too, though we might need better docs on how to run configure with specific flags when building from source.

This section of the installation docs mentions it, but it assumes you're building from a released source tarball, which already contains the configure script.

Whereas when building from a git checkout, which more and more people are likely to do these days, it's necessary to at least run make configure first (which, while slightly unusual, is I think justifiable).

[dimpase]

comment:2

I agree that this should include the needed changes. These docs need cleaning badly, see
e.g.

Building all of Sage with Clang is currently not supported, see trac ticket #12426

which is manifestly not true, etc.

[dimpase]

comment:3

OK, let me try to fix this.

[dimpase]

Commit: 4b5129c

[dimpase]

Branch: public/documentation/remove_sage_install_gcc

[dimpase]

comment:4

and this is only README.md fixes... (naturally, I could not stop until I made the whole text to reflect realty much better than it was)

[dimpase]

comment:5

SAGE_INSTALL_GCC is used for two more or less orthogonal purposes: get input from the user, and for updating the toolchain (that's where it set to/tested for exists value).

Refactoring this is going to be fun...

[sagetrac-git]

Changed commit from 4b5129c to a9c8ddd

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

a9c8ddd

marked SAGE_INSTALL_GCC obsolete, updated installation manual

[dimpase]

Author: Dima Pasechnik

[dimpase]

comment:7

Don't know whether we should document how to force building of GCC.
(using --without-system-gcc, that is).

It is still far from ideal, but already a step forward from the hugely obsolete installation docs.

[dimpase]

comment:9

these are really badly overdue documentation changes. let us get them in soon.

[mkoeppe]

Reviewer: Matthias Koeppe

[mkoeppe]

comment:10

Looks good to me. A major improvement.

[vbraun]

Changed branch from public/documentation/remove_sage_install_gcc to a9c8ddd