Setting environment variables:
EMSDK = /opt/emsdk
EM_CACHE = /opt/emsdk/upstream/emscripten/cache
EMSDK_NODE = /opt/emsdk/node/12.18.1_64bit/bin/node
error: undefined symbol: memset (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: _memset may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
emcc: error: '/opt/emsdk/node/12.18.1_64bit/bin/node /opt/emsdk/upstream/emscripten/src/compiler.js /tmp/tmp9uxny0lo.txt' failed (1)
make[1]: *** [Makefile:24: libmupdf.js] Error 1
make[1]: Leaving directory '/home/pedr0/local/src/mupdf-1.17.0-source/platform/wasm'