Comment 3 for bug 1665123

So the state yesterday was:

snap r439 had Mir 0.26.0
xenial overlay had Mir 0.26.1
snapped Mir was loading graphics-mesa-kms.so.12 (and failed)

snap r439 had Mir 0.26.0
zesty had Mir 0.26.0
snapped Mir was loading graphics-mesa-kms.so.11 (and worked fine)

After rebuiling the snap:

snap r442 has Mir 0.26.1
xenial overlay has Mir 0.26.1
snapped Mir loads graphics-mesa-kms.so.12 (and works)

snap r44 has Mir 0.26.1
zesty has Mir 0.26.0
snapped Mir loads graphics-mesa-kms.so.11 (and fails)

After installing Mir from zesty-proposed:

snap r44 has Mir 0.26.1
zesty-proposed has Mir 0.26.1
snapped Mir loads graphics-mesa-kms.so.12 (and works)