grpc-web: grpc-web plugin not working in GitHub Codespaces

I am running the code generator plugin in GitHub Codespaces and gett the following error:

/usr/local/bin/protoc-gen-grpc-web: 1: /usr/local/bin/protoc-gen-grpc-web: Not: not found
--grpc-web_out: protoc-gen-grpc-web: Plugin failed with status code 127.

protoc is installed and in the PATH and both binaries are executable (chmod +x …).

Do you have any thoughts on where I might start to resolve this?