Hi .. Enabling exceptions for WASM seems to conflict with an -fno-exceptions flag being used by emscripten during linking.
For example, if I add a try and catch in the example and build with:

bazel build //example:http_wasm_example.wasm --features=exceptions

The build fails with the following error:

jlbirch@jlbirch:~/proxy-wasm-cpp-sdk-jlb6740/example$ bazel build //example:http_wasm_example.wasm --features=exceptions --verbose_failures
INFO: Analyzed target //example:http_wasm_example.wasm (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
ERROR: /home/jlbirch/proxy-wasm-cpp-sdk-jlb6740/example/BUILD:5:21: Linking example/proxy_wasm_http_wasm_example failed: (Exit 1): emcc_link.sh failed: error executing command
(cd /home/jlbirch/.cache/bazel/_bazel_jlbirch/7341316095ecd002ea18765f811f48f4/sandbox/linux-sandbox/26/execroot/proxy_wasm_cpp_sdk &&
exec env -
EMCC_WASM_BACKEND=1
EM_BIN_PATH=external/emscripten_bin_linux
EM_CONFIG_PATH=external/emsdk/emscripten_toolchain/emscripten_config
PATH=/home/jlbirch/.cache/bazelisk/downloads/bazelbuild/bazel-4.1.0-linux-x86_64/bin:/home/jlbirch/.wasmer/bin:/home/jlbirch/emsdk:/home/jlbirch/emsdk/upstream/emscripten:/home/jlbirch/emsdk/node/14.18.2_64bit/bin:/opt/intel/oneapi/vtune/2022.2.0/bin64:/opt/intel/oneapi/vtune/latest/bin64:/opt/intel/oneapi/vtune/latest/android_target:/home/jlbirch/.wasmtime/bin:/home/jlbirch/.vscode-server/bin/6cba118ac49a1b88332f312a8f67186f7f3c1643/bin:/home/jlbirch/.local/bin:/home/jlbirch/.wasmer/bin:/home/jlbirch/.cargo/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/jlbirch/sde-external-9.0.0-2021-11-07-lin/:/home/jlbirch/wabt/build/:/home/jlbirch/node-v16.16.0-linux-x64/bin/:/home/jlbirch/.wasmer/globals/wapm_packages/.bin:/home/jlbirch/.wasmer/globals/wapm_packages/.bin
PWD=/proc/self/cwd
external/emsdk/emscripten_toolchain/emcc_link.sh @bazel-out/wasm-fastbuild-ST-7840e1c24980/bin/example/proxy_wasm_http_wasm_example-2.params)
Execution platform: @local_config_platform//:host

Use --sandbox_debug to see verbose messages from the sandbox
error: DISABLE_EXCEPTION_THROWING was set (likely due to -fno-exceptions), which means no C++ exception throwing support code is linked in, but exception catching code appears. Either do not set DISABLE_EXCEPTION_THROWING (if you do want exception throwing) or compile all source files with -fno-except (so that no exceptions support code is required); also make sure DISABLE_EXCEPTION_CATCHING is set to the right value - if you want exceptions, it should be off, and vice versa.
error: DISABLE_EXCEPTION_THROWING was set (likely due to -fno-exceptions), which means no C++ exception throwing support code is linked in, but exception catching code appears. Either do not set DISABLE_EXCEPTION_THROWING (if you do want exception throwing) or compile all source files with -fno-except (so that no exceptions support code is required); also make sure DISABLE_EXCEPTION_CATCHING is set to the right value - if you want exceptions, it should be off, and vice versa.
error: undefined symbol: __resumeException (referenced by top-level compiled C/C++ code)
warning: Link with -s LLD_REPORT_UNDEFINED to get more information on undefined symbols
warning: To disable errors for undefined symbols use -s ERROR_ON_UNDEFINED_SYMBOLS=0
warning: ___resumeException may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
emcc: error: '/home/jlbirch/.cache/bazel/_bazel_jlbirch/7341316095ecd002ea18765f811f48f4/sandbox/linux-sandbox/26/execroot/proxy_wasm_cpp_sdk/external/nodejs_linux_amd64/bin/node /home/jlbirch/.cache/bazel/_bazel_jlbirch/7341316095ecd002ea18765f811f48f4/external/emscripten_bin_linux/emscripten/src/compiler.js /tmp/tmpr68z5zhw.json' failed (returned 1)
Target //example:http_wasm_example.wasm failed to build
INFO: Elapsed time: 2.611s, Critical Path: 2.47s
INFO: 5 processes: 2 internal, 3 linux-sandbox.
FAILED: Build did NOT complete successfully

The line in building.py of a very recent version of emscripten that emits the -fno-exceptions looks like this:

if not settings.DISABLE_EXCEPTION_CATCHING:
args += ['-enable-emscripten-cxx-exceptions']

Is there a way to programmatically set the setting of DISABLE_EXCEPTION_CATCHING in bazel build files? Currently I am forced to comment out the lines here.