GnuPG 1.4 failed to build: duplicate symbol from wasm-ld when using extern in .h files

[Young-Lord]

Version of emscripten/emsdk:

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.71 (4171ae200b77a6c266b0e1ebb507d61d1ade3501)
clang version 20.0.0git (https:/github.com/llvm/llvm-project d6344c1cd0d099f8d99ee320f33fc9254dbe8288)
Target: wasm32-unknown-emscripten
Thread model: posix

Failing command line in full:
Sorry for not able to give a minimal reproduction. I can only attach full output log here. I've found #22629 and other issues, but no solution worked for me.

wget https://www.gnupg.org/ftp/gcrypt/gnupg/gnupg-1.4.23.tar.bz2
tar xvf gnupg-1.4.23.tar.bz2
cd gnupg-1.4.23
emconfigure ./configure --disable-agent-support --disable-photo-viewers --disable-exec --disable-threads
emmake make V=1 LDFLAGS=-v

The error from console output is similar to this:

/home/yang/wasm/emsdk/upstream/emscripten/emcc  -g -O2 -Wall -Wno-pointer-sign   -o gpgsplit gpgsplit.o ../cipher/libcipher.a ../mpi/libmpi.a ../util/libutil.a   ../intl/libintl.a    ../zlib/libzlib.a
wasm-ld: error: duplicate symbol: iobuf_debug_mode
>>> defined in mpicalc.o
>>> defined in ../mpi/libmpi.a(mpi-add.o)

wasm-ld: error: duplicate symbol: memory_debug_mode
>>> defined in mpicalc.o
>>> defined in ../mpi/libmpi.a(mpi-add.o)

wasm-ld: error: duplicate symbol: memory_stat_debug_mode
>>> defined in mpicalc.o
>>> defined in ../mpi/libmpi.a(mpi-add.o)

wasm-ld: error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
emcc: error: '/home/yang/wasm/emsdk/upstream/bin/wasm-ld -o mpicalc.wasm -L/home/yang/wasm/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten mpicalc.o ../cipher/libcipher.a ../mpi/libmpi.a ../util/libutil.a ../intl/libintl.a -lGL-getprocaddr -lal -lhtml5 -lstubs -lnoexit -lc -ldlmalloc -lcompiler_rt -lc++-noexcept -lc++abi-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr /tmp/tmpgfdpsqxhlibemscripten_js_symbols.so --export=_emscripten_stack_alloc --export=__get_temp_ret --export=__set_temp_ret --export=__wasm_call_ctors --export=emscripten_stack_get_current --export=_emscripten_stack_restore --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=main --export-if-defined=__main_argc_argv --export-table -z stack-size=65536 --no-growable-memory --initial-heap=16777216 --no-entry --table-base=1 --global-base=1024' failed (returned 1)

Here is full log: make.log

Full link command and output with -v appended:
make.2.log

P.S., GnuPG 2.x can build smoothly.