emcc warning emscipten a long time

I clone the git code and use 'emsdk install latest && emsdk activate latest && ./emsdk_env.sh'

when i use the sample 'hello'.

see this, and i wate one day has no result. why??

cache:WARNING: Accessing the Emscripten cache at "/home/openailab/workspace/workspace/wasm/emsdk/upstream/emscripten/cache" is taking a long time, another process should be writing to it. If there are none and you suspect this process has deadlocked, try deleting the lock file "/home/openailab/workspace/workspace/wasm/emsdk/upstream/emscripten/cache/cache.lock" and try again. If this occurs deterministically, consider filing a bug.

i use comm 'emcc hello.c -s WASM=1 -o hello.html'