rust nightly errors with doesn't have an adapter listed

[ctaggart]

With rust nightly, I'm getting one of these two errors:

error: import of `__wbg_cargowebsnippetc26ddf75f581148e029dfcd95c037bb50d502e43_f494f4a63cf92998` doesn't have an adapter listed
Error: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit code: 1

error: import of `__wbg_cargowebsnippetc26ddf75f581148e029dfcd95c037bb50d502e43_f494f4a63cf92998` doesn't have an import map item listed
Error: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit code: 1

I'm building with wasm-pack build --target web.

$ cargo install-update --list
Package           Installed  Latest    Needs update
wasm-bindgen-cli  v0.2.56    v0.2.56   No
wasm-pack         v0.8.1     v0.8.1    No

rustup default nightly
nightly-x86_64-apple-darwin unchanged - rustc 1.42.0-nightly (9b98af84c 2019-12-22)

It is working fine on rust stable.

[trivigy]

Same exact error here. Seems that even the hashes match up. Would greatly appreciate some recommendation on how to debug this. I am on a slightly newer nightly version. rustc 1.42.0-nightly (3a3f4a7cb 2019-12-28)

EDIT: One other thing that I tested is that this issue doesn't seem to exist in nightly-2019-12-20 but does happen beginning with nightly-2019-12-30.

error: import of `__wbg_cargowebsnippetc26ddf75f581148e029dfcd95c037bb50d502e43_f494f4a63cf92998` doesn't have an adapter listed
Error: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit code: 1

[alexcrichton]

Thanks for the report! The bad news is that this was a breakage caused by a behavior change in upstream Rust, but the good news is that our internal test suite caught it and I just was on break and wasn't around to fix it! I've posted a fix for this at #1942

[ctaggart]

Hope you had a wonderful break! Thanks for the fix. I really like wasm-bindgen.

[t-moe]

Without having a full reproducer at hand, my colleague observed
error: import of __wbindgen_array_new doesn't have an adapter listed
today when running wasm-bindgen on his mac...

he was also using rust nightly and a command like wasm-pack build --target browser --mode normal --no-typescript

anybody else?