Snapping webengine under ARM

Hey guys, I am trying to build a snap with QtWebEngine for rpi eglfs. So it builds fine. Qt apps work. But when trying to run apps that actually use webengine I am getting a crash in webengine process:
LaunchProcess: failed to execvp:
/snap/screenly-client/x40/usr/libexec
Trace/breakpoint trap

When running with LD_DEBUG I get this:
/snap/screenly-client/x40/bin/screenly-client: error: symbol lookup error: undefined symbol: nspr_use_zone_allocator (fatal)

any idea what this error can be related to? I am building latest Qt, using system libs as dependencies, the libs are actually present, but libnspr does not actually export that symbol. And I am not sure what actually needs it, as webengine code does not seem to use that function at all.