Mainly, because there's no current reason to install libjpeg.dylib. It's just a potentional source of confusion and breakage for the future. I'd feel differently if there were other uses of it. For instance, if someone were to wrap Dan Bloomberg's excellent Leptonica library at http://www.leptonica.org/. In that case, there might be some reason to have both PIL and Leptonica use the same libjpeg.
Bill On Nov 15, 11:58 pm, William Stein <wst...@gmail.com> wrote: > On Tue, Nov 15, 2011 at 10:52 PM, Bill Janssen <bill.jans...@gmail.com> wrote: > >> > Again, installing libjpeg.dylib and/or libpng.dylib into $SAGE_LOCAL/ > >> > lib has bad side effects on OS X, due to the use of DYLD_LIBRARY_PATH > >> > in the Sage framework overall. So, maybe make it an optional spkg, > >> > but having it as a required or standard spkg would be bad. > > >> We already install libpng.dylib standard in all copies of Sage on OS > >> X. There were issues, but they got sorted out a while ago. > > >> -- William > > > The reason this works on OS X is that the Sage version of the library > > is called libpng12.dylib, while the system version is libpng.dylib. > > This numbering is now built-in to libpng, but not to the jpeg > > libraries, so the same process won't protect you. > > > Basically, you can't safely override the library names you find in > > /System/Library/Frameworks/ApplicationServices.framework/Versions/A/ > > Frameworks/ImageIO.framework/Resources/, which are libjp2.dylib, > > libjpeg.dylib, libopenexr.dylib, libpng.dylib, libradience.dylib, > > libtiff.dylib, and libgif.dylib. By "override", I mean have libraries > > with the same name (differing only in case) prior to these libraries > > on the DYLD_LIBRARY_PATH. The version of libpng in /System is 1.4.3 > > on both my Leopard system and my Lion system. The version in > > sage-4.7.2 is 1.2.35. But the library name is different, so there's > > no problem. > > If all that is the case, why don't you name the jpeg library > libjpegsage.dylib or something, and slightly change the PIL build > script. > > > > > -- > > 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 > > athttp://groups.google.com/group/sage-devel > > URL:http://www.sagemath.org > > -- > William Stein > Professor of Mathematics > University of Washingtonhttp://wstein.org -- 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
