blank-canvas-0.6.3 depends on base-compat-batteries-0.10, which
depends on base-compat-0.10. This conflicts with the rest of the LTS
set, which uses base-compat-0.9. No base-compat-batteries-0.9 exists.
blank-canvas-0.6.2 only depends on base-compat >= 0.8 && < 0.10.