warnings building mediasoup-broadcaster-demo

I am on OSX 10.15. I have successfully built libwebrtc at m84 following the instructions in the docs. And it appears that the broadcaster demo is actually building. However, I am getting some strange warnings I would like to clear up. There are a lot of them but they generally take the form:

ld: warning: direct access in function 'webrtc::VP9EncoderImpl::GetEncoderInfo() const' from file '/Users/alexciarlillo/code/src/googlesource/webrtc-checkout/src/out/m84/obj/libwebrtc.a(vp9_impl.o)' to global weak symbol 'void rtc::webrtc_checks_impl::LogStreamer<>::Call<>(char const*, int, char const*)::t' from file 'CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o' means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

So a quick run down of my steps:

After setting up libwebrtc deps, checking out m84, etc. Build it like:

$ gn gen out/m84 --args='is_debug=false is_component_build=false is_clang=true rtc_include_tests=false rtc_use_h264=true use_rtti=true mac_deployment_target="10.11" use_custom_libcxx=false'

Checkout mediasoup-broadcaster-demo. Made some CMake changes to pull cpr as suggested, e.g.:

FetchContent_Declare(cpr GIT_REPOSITORY https://github.com/whoshuu/cpr.git GIT_TAG 4f0a0bac4feabc74dee4ef1f634ff0bf5dc7efcc) # latest master

(this works great btw rather than having cpr directly in the repo as a dep)


cmake . -Bbuild \                                                                                ─╯
-DLIBWEBRTC_INCLUDE_PATH:PATH=/Users/alexciarlillo/code/googlesource/webrtc-checkout/src \
-DLIBWEBRTC_BINARY_PATH:PATH=/Users/alexciarlillo/code/googlesource/webrtc-checkout/src/out/m84/obj \
-DOPENSSL_ROOT_DIR=/usr/local/Cellar/openssl@1.1/1.1.1h \

All good there.


make -C build

This is where I get the warnings above. It does build though and I can run it (but it doesn’t quite work):

❯ SERVER_URL=https://v3demo.mediasoup.org ROOM_ID=0prbwkxw build/broadcaster
[DEBUG] mediasoupclient::Initialize() | mediasoupclient v3.1.1
[INFO] welcome to mediasoup broadcaster app!

[INFO] verifying that room '0prbwkxw' exists...
[ERROR] unable to retrieve room info [status code:404, body:"<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<title>404 Not Found</title>
<h1>Not Found</h1>
<p>The requested URL /rooms/0prbwkxw was not found on this server.</p>

Any ideas would be appreciated. Thanks

After more digging I found this:

I’m not sure how I missed this in the docs the first time around… information overload I guess.