I'm packaging a Windows 32bit (as well as x64) application from an x64 AppVeyor VM with Node x64.
My app has a dependency on leveldown v5.0.2 which does not provide 32bit prebuilt binaries anymore.
As can be seen in the following logs, electron-rebuild seems to succeed at compiling it itself:
rebuilding native dependencies dependencies=@atom/watcher@1.3.1, @gyselroth/windows-fsstat@0.0.7, dtrace-provider@0.8.8, leveldown@5.0.2 platform=win32 arch=ia32
install prebuilt binary name=@atom/watcher version=1.3.1 platform=win32 arch=ia32
build native dependency from sources name=@atom/watcher
version=1.3.1
platform=win32
arch=ia32
reason=prebuild-install failed with error (run with env DEBUG=electron-builder to get more information)
error=prebuild-install info begin Prebuild-install version 5.2.4
prebuild-install info looking for cached prebuild @ C:\Users\appveyor\AppData\Roaming\npm-cache\_prebuilds\0f981f-watcher-v1.3.1-electron-v70-win32-ia32.tar.gz
prebuild-install http request GET https://github.com/atom/watcher/releases/download/v1.3.1/watcher-v1.3.1-electron-v70-win32-ia32.tar.gz
prebuild-install http 404 https://github.com/atom/watcher/releases/download/v1.3.1/watcher-v1.3.1-electron-v70-win32-ia32.tar.gz
prebuild-install WARN install No prebuilt binaries found (target=5.0.0 runtime=electron arch=ia32 libc= platform=win32)
rebuilding native dependency name=@atom/watcher version=1.3.1
rebuilding native dependency name=@gyselroth/windows-fsstat version=0.0.7
rebuilding native dependency name=dtrace-provider version=0.8.8
rebuilding native dependency name=leveldown version=5.0.2
packaging platform=win32 arch=ia32 electron=5.0.0 appOutDir=dist\win-ia32-unpacked
downloading url=https://github.com/electron/electron/releases/download/v5.0.0/electron-v5.0.0-win32-ia32.zip size=61 MB parts=4
downloaded url=https://github.com/electron/electron/releases/download/v5.0.0/electron-v5.0.0-win32-ia32.zip duration=2.321s
building target=nsis file=dist\Cozy Drive Setup 3.16.0.exe archs=x64, ia32 oneClick=true perMachine=false
downloading url=https://github.com/electron-userland/electron-builder-binaries/releases/download/nsis-3.0.3.2/nsis-3.0.3.2.7z size=1.4 MB parts=1
downloaded url=https://github.com/electron-userland/electron-builder-binaries/releases/download/nsis-3.0.3.2/nsis-3.0.3.2.7z duration=700ms
However, when the app is launched on a x86 Windows, it fails with the following error:
Error: No native build was found for runtime=electron abi=70 platform=win32glibc arch=ia32

This seems to happen when we load leveldown.
I couldn't find any solution to this problem and figured this could be a configuration problem when running electron-builder for another architecture.
I'm packaging a Windows 32bit (as well as x64) application from an x64 AppVeyor VM with Node x64.
My app has a dependency on leveldown v5.0.2 which does not provide 32bit prebuilt binaries anymore.
As can be seen in the following logs, electron-rebuild seems to succeed at compiling it itself:
However, when the app is launched on a x86 Windows, it fails with the following error:
This seems to happen when we load leveldown.
I couldn't find any solution to this problem and figured this could be a configuration problem when running electron-builder for another architecture.