cargo should automatically enable an example's required features

[Lokathor]

Describe the problem you are trying to solve If you attempt to run an example with a required feature that's not a default feature of the crate, cargo prints an error message.

Describe the solution you'd like Instead, cargo should "do what I mean": just enable any additional required features for that example and then run the example.

Notes A similar change can be made for test and bins.

cc @joshtriplett

[joshtriplett]

I think this would be reasonable, as long as Cargo printed a message saying that was what it was doing. For instance:

Example `abc` requires feature `xyz`; rebuilding crate with feature `xyz`...

[pksunkara]

Duplicate of #4663?

[Lokathor]

sure looks that way. closing.