Full log: pastebin link
Log is from unity 2020.01 beta 4 but same log is generated from beta 8, 2018.4.23f and 2019.3.13f fresh install via administration right on unity hub, and empty new scene.
WebGL builds always fail with emscripten_fastcomp_win on archive ‘libcxx.a’, but used to build successful with unity 5.
Took weeks to search, even asking emscripten, still no luck. I am desperate.
OS details in log, in case TL;DR: running on Win10 x64.
Try going to your unity hub folder then go to playback engines and delete WebGL then redownload the WebGL module from the build settings of your game
Already reinstalled unity itself way more than 10 times now. Just removed and reinstalled WebGL support as you’ve said, still get exact same error.
stderr:extract archive contents( C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten_FastComp_Win\cache\asmjs\libcxx.a) failed with error: Command ‘[‘C:/Program Files/Unity/Hub/2019.3.14f1/Editor/Data/PlaybackEngines/WebGLSupport\BuildTools\Emscripten_FastComp_Win\llvm-ar.exe’, ‘xo’, ‘C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten_FastComp_Win\cache\asmjs\libcxx.a’]’ returned non-zero exit status 1Traceback (most recent call last): File “C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emcc.py”, line 3063, in sys.exit(run()) File “C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\emcc.py”, line 1675, in run final = shared.Building.link(linker_inputs, DEFAULT_FINAL, force_archive_contents=force_archive_contents, temp_files=misc_temp_files, just_calculate=just_calculate) File “C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\tools\shared.py”, line 2029, in link Building.read_link_inputs([x for x in files if not x.startswith(‘-’)]) File “C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten\tools\shared.py”, line 1879, in read_link_inputs raise Exception('llvm-ar failed on archive ’ + archive_names[n] + ‘!’)Exception: llvm-ar failed on archive C:\Program Files\Unity\Hub\2019.3.14f1\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\Emscripten_FastComp_Win\cache\asmjs\libcxx.a!
What is wrong with libcxx.a? It can’t be defective as all libcxx.a shipped by unity installations had exact same bytes.