On my system upgrading to libtool 2.2 causes the following builds to fail during the autoconf/automake/configure process: media-libs/faad2-2.6.1: dev-libs/libusb-0.1.12-r1 app-text/hunspell-1.2.2_beta dev-db/mysql-5.0.54 x11-libs/gtk+-2.12.8 dev-util/subversion-1.4.6-r1 media-libs/fontconfig-2.5.0-r1 dev-dotnet/libgdiplus-1.2.6 dev-python/pygobject-2.14.1 sys-apps/hal-0.5.10 media-gfx/graphviz-2.16.1-r3 gnome-extra/gnome-power-manager-2.20.2 app-editors/gedit-2.20.4-r1 app-text/evince-2.20.2 media-video/totem-2.20.3 dev-lang/mono-1.2.6-r2 The actual error gotten varies by package, but all appear to be libtool related. I can attach logs if necessary. Note that these packages build fine with libtool 1.5.26. I really don't know why mono failed. The actual error message didn't link to anything libtool-related, however it builds successfully with libtool 1.5.26.
Since there's no universal fix, unfortunately we need one bug per package if there's not already one... :/ Make them block Bug 212763. Thanks. *** This bug has been marked as a duplicate of bug 212763 ***