On Sat, Jan 30, 2010 at 10:16 PM, Dr. David Kirkby <david.kir...@onetel.net> wrote: > Starting to build Sage, then finding the python builds, but finds to find > the hashlib module is a bit irritating. There is is a specific test for this > in spkg-install. > > > ------------------------- > # Make sure sufficient crypto support is available in the built python. > # This is critical. > python -c "import hashlib" > > if [ $? -eq 0 -a -f "$SAGE_LOCAL/bin/python" ]; then > echo "hashlib module imported" > exit 0 > else > echo "hashlib module failed to import" > exit 1 > fi > ----------------------------- > > Faillure to build the haslib module results from a failure to find the SSL > libraries. Would it not be more sensible to check for these in prereq, then > exit if they are not found. It would save someone getting half a build. > > As a second point, would it seem sensible to add a slightly more informative > error message to python's spkg-install, to indicate the probably cause of > the problem (lack of OpenSSL library) and how one might remedy that? > > If there is agreement on these, I'll create two trac tickets, and address > them individually.
If we require SSL, then perhaps we should: (1) get rid of GNUtls, libcdk, libgcrypt, libgpgerror, and anything other spkg related to that stack. (2) should include openssl in Sage. The reason is that the openssl license is GPL-incompatible. If Sage requires it to run, then we have to think about the implications of that. Technically, I think none of the GPL-'d parts of the Sage binary link with any of the crypto/ssl libraries. I think the only thing in all of Sage that binary links directly with ssl is Python itself. It's a possibly subtle license question whether we can legally ship openSSL or not. Personally, I believe it is technically legal. However, we would certainly have to change the statement in the README.txt about all components of SAGE being GPLv2+ compatible. Note that a few years ago, Sage did ship opensll and not ship the gnutls stack. Then a student in my Sage class pointed out that openssl is licensed in a GPL-incompatible way, and that's when we switched to GNUtls. Overall, unfortunately it seems that the GNUtls library and stack is unfortunately not a drop-in replacement for openssl, and seems to be generally less popular and less well supported. That things would turn out this way was much less clear 3-4 years ago. -- William -- 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
