Building Magnum on Emscripten 2.0.17 to 2.0.24 fails with undefined symbol: malloc

[werto87]

Hi, when I compile magnum to wasm i get the error "Could NOT find Corrade (missing: Utility)".
I setup the toolchain file ("set(EMSCRIPTEN_PREFIX "/usr/lib/emscripten")")
and build corrade for wasm.
Then I execute
"makepkg -fp PKGBUILD-emscripten-wasm" in "/magnum/package/archlinux"
and get the output:
==> Making package: emscripten-magnum dev.wasm-1 (2021-05-26T00:44:21 CEST)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
==> Extracting sources...
==> Removing existing $pkgdir/ directory...
==> Starting build()...
-- The CXX compiler identification is Clang 13.0.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/lib/emscripten/em++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at /usr/share/cmake-3.20/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
Could NOT find Corrade (missing: Utility)
Call Stack (most recent call first):
/usr/share/cmake-3.20/Modules/FindPackageHandleStandardArgs.cmake:594 (_FPHSA_FAILURE_MESSAGE)
modules/FindCorrade.cmake:605 (find_package_handle_standard_args)
CMakeLists.txt:51 (find_package)

Configuring incomplete, errors occurred!
See also "/home/walde/aur/magnum/build-emscripten-wasm/CMakeFiles/CMakeOutput.log".
See also "/home/walde/aur/magnum/build-emscripten-wasm/CMakeFiles/CMakeError.log".
==> ERROR: A failure occurred in build().
Aborting...

/usr/lib/emscripten/system/lib" contains:
libCorradeInterconnect.so, libCorradePluginManager.so, libCorradeTestSuite.so, libCorradeUtility.so

[mosra]

Hi!

Corrade was built and installed using the PKGBUILD-emscripten-wasm in corrade as well, using the same toolchain file? It's strange that it installed *.sos, it should be generating static libraries with the *.bc extension.

Magnum (and the toolchain both Corrade and Magnum use) then looks for *.bc files and because there are only *.sos, it fails to find them.

[werto87]

Hi, thank you for the clues. I will try a fresh start and will report what kind of files I get.

[werto87]

I got the .bc files.

when running "sudo pacman -U emscripten-corrade-dev.wasm-1-any.pkg.tar.zst" i get some warnings:
warning: could not get file information for usr/lib/emscripten/system/lib/libCorradeInterconnect.so
warning: could not get file information for usr/lib/emscripten/system/lib/libCorradePluginManager.so
warning: could not get file information for usr/lib/emscripten/system/lib/libCorradeTestSuite.so
warning: could not get file information for usr/lib/emscripten/system/lib/libCorradeUtility.so

I will try to build magnum now

[mosra]

Looks like some stale files from a manual install? :)

To ensure you have a clean setup, I'd suggest manually removing the whole /usr/lib/emscripten and installing emscripten + emscripten-corrade again :)

[werto87]

magnum finds corrade now

-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility PluginManager
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility Main TestSuite
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility PluginManager

I think the problem was that I had some .so files in the emscripten/system folder.

[werto87]

Looks like some stale files from a manual install? :)

To ensure you have a clean setup, I'd suggest manually removing the whole /usr/lib/emscripten and installing emscripten + emscripten-corrade again :)

Yeah I was fighting hard :)

[werto87]

I am getting another error

[walde@localhost archlinux]$ makepkg --nocheck -fp PKGBUILD-emscripten-wasm
==> Making package: emscripten-magnum dev.wasm-1 (2021-05-26T16:19:06 CEST)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
==> Extracting sources...
==> Removing existing $pkgdir/ directory...
==> Starting build()...
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility PluginManager
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility Main TestSuite
-- Found Corrade: /usr/lib/emscripten/system/include found components: Containers rc Utility PluginManager
-- Configuring done
-- Generating done
-- Build files have been written to: /home/walde/aur/magnum/build-emscripten-wasm
[7/119] Linking CXX executable Release/bin/magnum-gl-info.js
FAILED: Release/bin/magnum-gl-info.js
: && /usr/lib/emscripten/em++ -s WASM=1 -Wno-warn-absolute-paths -DNDEBUG -O3 -O3 -DNDEBUG -s WASM=1 -O3 --llvm-lto 1 src/Magnum/Platform/CMakeFiles/magnum-gl-info.dir/gl-info.cpp.o -o Release/bin/magnum-gl-info.js Release/lib/MagnumGL.bc Release/lib/MagnumWindowlessEglApplication.bc Release/lib/MagnumGL.bc Release/lib/Magnum.bc /usr/lib/emscripten/system/lib/CorradeUtility.bc /usr/lib/emscripten/system/lib/CorradeUtility.bc -lGL && cd /home/walde/aur/magnum/build-emscripten-wasm/src/Magnum/Platform && /usr/bin/cmake -E copy_if_different /home/walde/aur/magnum/src/Magnum/Platform/WebApplication.css /home/walde/aur/magnum/src/Magnum/Platform/WindowlessEmscriptenApplication.js /home/walde/aur/magnum/build-emscripten-wasm/Release/bin && /usr/bin/cmake -E copy_if_different /home/walde/aur/magnum/src/Magnum/Platform/gl-info.html /home/walde/aur/magnum/build-emscripten-wasm/Release/bin/magnum-gl-info.html
emcc:WARNING: --llvm-lto ignored when using llvm backend
error: undefined symbol: malloc (referenced by $stringToNewUTF8__deps: ['malloc'], referenced by glGetString__deps: ['$stringToNewUTF8','$GL'], 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: _malloc may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: '/usr/bin/node /usr/lib/emscripten/src/compiler.js /tmp/tmpecl8dtvf.txt' failed (1)
[14/119] Building CXX object src/Magnum/SceneGr...eFiles/MagnumSceneGraph.dir/instantiation.cpp.o
ninja: build stopped: subcommand failed.
==> ERROR: A failure occurred in build().
Aborting...

[mosra]

Looks like some fancy new emscripten breakage (this happens all the time, unfortunately). What version are you on? Locally I'm on 2.0.10 and it works here -- can you try downgrading? Get a package from ArchLinux Archive, for example.

I'll have to fix this of course, but a downgrade could be a temporary solution to unblock you.

[werto87]

I am on 2.0.17.
I will try 2.0.10

[werto87]

I was not able to get emscripten 2.0.10 running from arch aur. I will try to use emsdk to get to version 2.0.10.

[werto87]

I was able to build magnum with emscripten 2.0.10 from emsdk.
Note: if you are on arch linux and want to build magnum for wasm and are using emsdk you need to remove the dependency 'emscripten' from the PKGBUILD-emscripten-wasm file.
Thank you @mosra for your help.

[mosra]

Keeping this open as a reminder to fix the build issue ;)

FYI, here's older Emscripten versions (this is what I'm always doing, in case I upgrade and get a breakage and I have nothing in /var/cache/pacman/pkg anymore, I get it from here): https://archive.archlinux.org/packages/e/emscripten/