Because cool_ui 1.3.0 depends on back_button_interceptor 6.0.0 and no versions of cool_ui match >1.3.0 <2.0.0, cool_ui ^1.3.0 requires back_button_interceptor 6.0.0.
So, because aaa depends on both back_button_interceptor ^6.0.2 and cool_ui ^1.3.0, version solving failed.
Because cool_ui 1.3.0 depends on back_button_interceptor 6.0.0 and no versions of cool_ui match >1.3.0 <2.0.0, cool_ui ^1.3.0 requires back_button_interceptor 6.0.0. So, because aaa depends on both back_button_interceptor ^6.0.2 and cool_ui ^1.3.0, version solving failed.