can't find crate for `core`

[yihan0512]

Hello, I try to build the project, but got this error:

error[E0463]: can't find crate forcore| = note: thewasm32-unknown-unknown` target may not be installed

error: aborting due to previous error

For more information about this error, try rustc --explain E0463.
error: could not compile cfg-if.

To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
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