If gnome-contacts is built against gtk < 3.16 it will fail to build like this:


/bin/bash ../libtool  --tag=CC   --mode=link gcc  -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall  -Wl,-z,relro -Wl,-z,defs -Wl,-O1 -Wl,--as-needed -o gnome-contacts contacts-app.o contacts-address-map.o contacts-contact.o contacts-contact-sheet.o contacts-contact-editor.o contacts-contact-pane.o contacts-types.o contacts-list-pane.o contacts-linked-accounts-dialog.o contacts-linking.o contacts-store.o contacts-view.o contacts-utils.o contacts-avatar-dialog.o contacts-accounts-list.o contacts-contact-frame.o contacts-window.o main.o  um-crop-area.o contact-resources.o contacts-esd-setup.o  cheese-flash.o  -Wl,--export-dynamic -lgmodule-2.0 -pthread -lgnome-desktop-3 -lfolks-telepathy -lfolks-eds -lfolks -lnotify -ltelepathy-glib -lebook-1.2 -ledata-book-1.2 -lebackend-1.2 -lebook-contacts-1.2 -ledataserver-1.2 -ledataserverui-1.2 -ledataserver-1.2 -Wl,--export-dynamic -lgmodule-2.0 -pthread -lcamel-1.2 -lsqlite3 -lnss3 -lnssutil3 -lsmime3 -lssl3 -lplds4 -lplc4 -lnspr4 -lsecret-1 -lxml2 -lsoup-2.4 -lgoa-1.0 -lgee-0.8 -lchamplain-0.12 -lclutter-gtk-1.0 -lclutter-1.0 -lcogl-path -lcogl-pango -lcogl -lgmodule-2.0 -pthread -lEGL -lXrandr -ljson-glib-1.0 -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXi -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgeocode-glib -lgio-2.0 -lgobject-2.0 -lglib-2.0  -lm ../libgd/libgd.la -lcheese-gtk -lgtk-3 -lcheese -lclutter-1.0 -lcogl-path -latk-1.0 -lcogl-pango -lcogl -lgmodule-2.0 -pthread -lEGL -lXrandr -ljson-glib-1.0 -lgio-2.0 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -lcairo-gobject -lcairo -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXi -lgdk_pixbuf-2.0 -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0  
libtool: link: gcc -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall -Wl,-z -Wl,relro -Wl,-z -Wl,defs -Wl,-O1 -Wl,--as-needed -o gnome-contacts contacts-app.o contacts-address-map.o contacts-contact.o contacts-contact-sheet.o contacts-contact-editor.o contacts-contact-pane.o contacts-types.o contacts-list-pane.o contacts-linked-accounts-dialog.o contacts-linking.o contacts-store.o contacts-view.o contacts-utils.o contacts-avatar-dialog.o contacts-accounts-list.o contacts-contact-frame.o contacts-window.o main.o um-crop-area.o contact-resources.o contacts-esd-setup.o cheese-flash.o -Wl,--export-dynamic -pthread -Wl,--export-dynamic -pthread -pthread -pthread  -lgnome-desktop-3 -lfolks-telepathy -lfolks-eds -lfolks -lnotify -ltelepathy-glib -lebook-1.2 -ledata-book-1.2 -lebackend-1.2 -lebook-contacts-1.2 -ledataserverui-1.2 -ledataserver-1.2 -lcamel-1.2 /usr/lib/x86_64-kfreebsd-gnu/libsqlite3.so -lnss3 -lnssutil3 -lsmime3 -lssl3 -lplds4 -lplc4 -lnspr4 -lsecret-1 -lxml2 -lsoup-2.4 -lgoa-1.0 -lgee-0.8 -lchamplain-0.12 -lclutter-gtk-1.0 -lgeocode-glib ../libgd/.libs/libgd.a -lm -lcheese-gtk -lgtk-3 -lcheese -lclutter-1.0 -lcogl-path -latk-1.0 -lcogl-pango -lcogl -lgmodule-2.0 -lEGL -lXrandr -ljson-glib-1.0 -lgio-2.0 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -lcairo-gobject -lcairo -lX11 -lXext -lXdamage -lXfixes -lXcomposite -lXi -lgdk_pixbuf-2.0 -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -pthread
contacts-contact.o: In function `contacts_contact_presence_construct':
/«PKGBUILDDIR»/src/contacts-contact.c:1208: undefined reference to `gtk_label_set_xalign'
contacts-contact-sheet.o: In function `contacts_contact_sheet_add_row_with_button':
/«PKGBUILDDIR»/src/contacts-contact-sheet.c:306: undefined reference to `gtk_label_set_xalign'
contacts-contact-sheet.o: In function `contacts_contact_sheet_add_row_with_label':
/«PKGBUILDDIR»/src/contacts-contact-sheet.c:399: undefined reference to `gtk_label_set_xalign'
/«PKGBUILDDIR»/src/contacts-contact-sheet.c:411: undefined reference to `gtk_label_set_xalign'
contacts-contact-sheet.o: In function `contacts_contact_sheet_update':
/«PKGBUILDDIR»/src/contacts-contact-sheet.c:803: undefined reference to `gtk_label_set_xalign'
contacts-contact-sheet.o:/«PKGBUILDDIR»/src/contacts-contact-sheet.c:354: more undefined references to `gtk_label_set_xalign' follow
collect2: error: ld returned 1 exit status

gtk_label_set_xalign  was introduced by gtk 3.16.
https://developer.gnome.org/gtk3/stable/GtkLabel.html#gtk-label-set-xalign