gegl fails to build with Debian oldstable due to use of g_memdup2
GIMP 2.10 CI uses Debian oldstable which fails building gegl:
/usr/bin/ld: gegl/libgegl-0.4.so.0.446.1.p/gegl-matrix.c.o: in function `gegl_matrix3_copy':
/builds/GNOME/gimp/_gegl/_build/../gegl/gegl-matrix.c:155: undefined reference to `g_memdup2'
/usr/bin/ld: gegl/libgegl-0.4.so.0.446.1.p/graph_gegl-node.c.o: in function `gegl_node_invalidated':
/builds/GNOME/gimp/_gegl/_build/../gegl/graph/gegl-node.c:795: undefined reference to `g_memdup2'
I see that GIMP only changed to g_memdup2 for the master branch, not for 2.10, because that function is only available starting from GLib 2.68.0, see gimp@49e53424.
This function was added to gegl in version 0.4.46. One option is to use an older version of gegl for our 2.10 CI. For gegl itself options are to raise the minimum GLib version, or add a conditional define to select which version of g_memdup to use.