In ICU4X we're moving towards no_std support, and this means that by default the Error trait is not implemented. It's possible to explicitly enable the "std" feature and have it be enabled, however it seems like it's unnecessary to require Error on the error associated types since none of Errors functionality is actually used — perhaps we should just require Debug+Display, or maybe even just one or none of those traits. In general we should require the traits we need.
In ICU4X we're moving towards
no_stdsupport, and this means that by default theErrortrait is not implemented. It's possible to explicitly enable the"std"feature and have it be enabled, however it seems like it's unnecessary to requireErroron the error associated types since none ofErrors functionality is actually used — perhaps we should just requireDebug+Display, or maybe even just one or none of those traits. In general we should require the traits we need.