In a recentish update to the prereq script (from 0.3 0.4) http://trac.sagemath.org/sage_trac/ticket/7021
I added a check on gcc version. The following happens. 1) gcc 4.0.0 exits, saying its buggy. 2) gcc >= 4.0.1, runs ok 3) gcc < 4.3, saying its too old. 4) 4.3.x, issues a warning, but allows to continue. I've just run it on my Ultra 27, and without changing the compilers, it uses the default gcc (a 3.4.x), and so I got to case 4. The warning is as clear as I could make it. checking gcc version... 3.4.3 checking if g++ accepts -dumpversion option... yes checking g++ version... 3.4.3 configure: Good, gcc and g++ are the same version (3.4.3) configure: Later, it will be checked if GCC 3.4.3 is suitable configure: WARNING: ****************************************************** configure: WARNING: ****************************************************** configure: WARNING: ****************************************************** configure: WARNING: GCC 3.4.3 is too old and can not build Sage. configure: WARNING: Please use a gcc of at least 4.0.1 configure: WARNING: if you just want Sage to build without problems. configure: WARNING: configure: WARNING: However, rather than exit as this point, the Sage configure: WARNING: build will continue, in case you want to debug configure: WARNING: a package, that will not build without a later GCC, configure: WARNING: but you want to try getting it to work with configure: WARNING: GCC 3.4.3. At the time of writing, (28th Sept 2009) configure: WARNING: 'ratpoints' was a program, needing GCC 4.0.1 configure: WARNING: which is later than would be ideal. configure: WARNING: ****************************************************** configure: WARNING: ****************************************************** configure: WARNING: ****************************************************** That is pretty clear, but it flies past so quick on my Ultra 27 that I think it could easily be missed. I'm wondering if we should exit if gcc < 4.0.1, and only allow gcc 4.3.x versions to continue if some environment variable is set. So it instead issues a message telling someone to set the environment variable SAGE_LET_ME_USE_OLD_GCC to "yes" if they wish to use a gcc 4.3.x. When I first wrote the script, I did it on a Sun SPARC with 1200 MHz processors. The warning could at least be seen on that. On the Ultra 27, with a 4-core 3.33 GHz CPU, it will be missed, as the warning is issued far quicker than anyone could ever read it. Dave -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
