error: unexpected `--cfg emscripten_wasm_eh` flag
   |
   = note: config `emscripten_wasm_eh` is only supposed to be controlled by `-Z emscripten_wasm_eh`
   = note: manually setting a built-in cfg can and does create incoherent behaviors
   = note: `#[deny(explicit_builtin_cfgs_in_flags)]` on by default

error: aborting due to 1 previous error