Let the user override MACOSX_DEPLOYMENT_TARGET

[nexttime]

In sage-env, we currently have:

# Mac OS X-specific setup
if [ `uname` = "Darwin" ]; then
    # set MACOSX_DEPLOYMENT_TARGET -- if set incorrectly, this can
    # cause lots of random "Abort trap" issues on OSX. see trac
    # #7095 for an example.
    MACOSX_VERSION=`uname -r | awk -F. '{print $1}'`
    MACOSX_DEPLOYMENT_TARGET=10.$[$MACOSX_VERSION-4]
    export MACOSX_DEPLOYMENT_TARGET
fi

With binary distributions of Sage, e.g. when trying to install an optional spkg, this can lead to errors like

configure:3166: checking whether the C compiler works
configure:3188: gcc    conftest.c  >&5
ld: library not found for -lcrt1.10.6.o
collect2: error: ld returned 1 exit status
configure:3192: $? = 1
configure:3230: result: no

hidden in config.log, the visible configure error message being

checking for gcc... gcc
checking whether the C compiler works... no
configure: error: in `/Applications/sage/local/var/tmp/sage/build/<package>/src':
configure: error: C compiler cannot create executables
See `config.log' for more details

At least as a work-around, the user should be able to set MACOSX_DEPLOYMENT_TARGET to some other value (e.g. 10.4) to get past such errors.

Setting a different target may make sense for developers (using Sage built from source) as well.

CC: @jhpalmieri

Component: build

Keywords: Xcode GCC -mmacosx-version-min compiler cannot create executables Darwin Mavericks MacApp bdist binary distribution

Issue created by migration from https://trac.sagemath.org/ticket/16312

[nexttime]

comment:1

I think #7095 (a huge ticket dealing with a couple of issues) is no longer (or not really) relevant here; there's some discussion of MACOSX_DEPLOYMENT_TARGET though, see #7095 comment:36 ff.

[nexttime]

comment:2

P.S.: Note that we meanwhile build most if not all parts of Sage with our own FSF GCC; Apple's GCC is only used to bootstrap our GCC (and to build some Objective C[++] files IIRC).

[mkoeppe]

comment:4

The code that was setting MACOSX_DEPLOYMENT_TARGET was removed in #18272, so we can close this ticket.

[jhpalmieri]

comment:5

Sounds good.