When compiling with USE_ICU, I'm getting the following error:

no symbols
no symbols
no symbols
no symbols
wasm-ld: error: /emsdk/.data/cache/wasm-obj/libicuuc.a(udata_a5e23168.cpp.o): undefined symbol: icudt62_dat
wasm-ld: error: /emsdk/.data/cache/wasm-obj/libicuuc.a(udata_a5e23168.cpp.o): undefined symbol: icudt62_dat
shared:ERROR: '/emsdk/upstream/bin/wasm-ld -o /tmp/emscripten_temp__hLcSu/x2t.wasm --allow-undefined --lto-O0 --no-check-features ./build/bin/linux_32/x2t.bc -L/emsdk/upstream/emscripten/system/local/lib ./build/lib/linux_32/libCryptoPPLib.a -L/emsdk/upstream/emscripten/system/lib ./build/lib/linux_32/libXlsFormatLib.a -L/emsdk/.data/cache/wasm-obj ./build/lib/linux_32/libkernel.so ./build/lib/linux_32/libgraphics.so ./build/lib/linux_32/libUnicodeConverter.so ./Common/3dParty/boost/boost_1_58_0/stage/lib/libboost_regex.a /emsdk/.data/cache/wasm-obj/libicuuc.a /emsdk/.data/cache/wasm-obj/libc-mt.a /emsdk/.data/cache/wasm-obj/libcompiler_rt.a /emsdk/.data/cache/wasm-obj/libc-wasm.a /emsdk/.data/cache/wasm-obj/libc++-mt-noexcept.a /emsdk/.data/cache/wasm-obj/libc++abi-mt-noexcept.a /emsdk/.data/cache/wasm-obj/libdlmalloc-mt.a /emsdk/.data/cache/wasm-obj/libpthread-mt.a /emsdk/.data/cache/wasm-obj/libc_rt_wasm.a --import-memory --import-table --shared-memory -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --strip-debug --export __wasm_call_ctors --export __data_end --export main --export malloc --export free --export setThrew --export __errno_location --export fflush --export emscripten_get_global_libc --export __pthread_tsd_run_dtors --export _register_pthread_ptr --export pthread_self --export __emscripten_pthread_data_constructor --export emscripten_futex_wake --export memalign --export usleep --export _ZSt18uncaught_exceptionv --export htonl --export htons --export ntohs --export realloc --export _get_tzname --export _get_daylight --export _get_timezone --export _get_environ --export emscripten_builtin_memalign --export emscripten_builtin_free -z stack-size=5242880 --initial-memory=149880832 --no-entry --max-memory=149880832 --global-base=1024' failed (1)

Here is the final build command:

gcc -Wl,--no-check-features -O0 -s USE_ICU=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s USE_PTHREADS=1 -s EXTRA_EXPORTED_RUNTIME_METHODS=["ccall"] -s EXPORT_ALL=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s TOTAL_MEMORY=149880832 -s WASM=1 ./build/bin/linux_32/x2t
.bc ./build/lib/linux_32/libCryptoPPLib.a ./build/lib/linux_32/libXlsFormatLib.a ./build/lib/linux_32/libkernel.so ./build/lib/linux_32/libgraphics.so ./build/lib/linux_32/libUnicodeConverter.so ./Common/3dParty/boost/boost_1_58_0/stage/lib/libboo
st_regex.a -lnodefs.js -o x2t.js

The build works when not using USE_ICU=1 but I'm then missing the icu methos:

warning: undefined symbol: ucnv_close_62
warning: undefined symbol: ucnv_fromUnicode_62
warning: undefined symbol: ucnv_getCCSID_62
warning: undefined symbol: ucnv_getMaxCharSize_62
warning: undefined symbol: ucnv_getMinCharSize_62
warning: undefined symbol: ucnv_getName_62
warning: undefined symbol: ucnv_openCCSID_62
warning: undefined symbol: ucnv_open_62
warning: undefined symbol: ucnv_toUnicode_62

which makes some part of the code fail while other parts are working.

It seems the libicudata is normally a separate library but it does not seem to be build in the ICU port.

If more info is needed I'm happy to provide it.