Failed assert in AsyncWrap::MakeCallback(uint32_t, int, Handle) from test-timers-unref.js on ARM

[rvagg]

Only seen on ARMv7 and goes away when you comment out this line (which does t.unref.bind(t)).

node: ../src/async-wrap-inl.h:245: v8::Handle<v8::Value> node::AsyncWrap::MakeCallback(uint32_t, int, v8::Handle<v8::Value>*): Assertion `cb->IsFunction()' failed.

https://jenkins-node-forward.nodesource.com/job/iojs+v0.12+multi/nodes=node-forward-nodesource-armv7-ubuntu1404/13/console

Could this be a libuv thing perhaps?

ARMv7 machine now hooked up to the CI cluster and will run with the rest of them.

[bnoordhuis]

It's at least partially a bug in async-wrap-inl.h because the code first casts to v8::Function before checking whether the object is really a function.

That's not the root cause, though. The error message suggests that timer[0] (that's where JS land stores the timeout callback) is not a function. Can I get access to that machine? I probably have to do some printf-style debugging to figure out where things go wrong.

[rvagg]

will privmsg on irc

[bnoordhuis]

Short status update: the callback field is undefined, hence the assert.

(gdb) call (*('v8::internal::Object'**) 0x11ed4a8)->Print()
0x5b079385: [JSObject]
 - map = 0x5f20fb01 [FAST_HOLEY_ELEMENTS]
 - prototype = 0x5b0639d9
 {
   #domain: 0x47e08091 <undefined> (field at offset 0)
   0: 0x47e08091 <undefined>
   1: 0x47e080a1 <the hole>
   2: 0x47e080a1 <the hole>
   3: 0x47e080a1 <the hole>
   4: 0x47e080a1 <the hole>
   5: 0x47e080a1 <the hole>
   6: 0x47e080a1 <the hole>
   7: 0x47e080a1 <the hole>
   8: 0x47e080a1 <the hole>
   9: 0x47e080a1 <the hole>
   10: 0x47e080a1 <the hole>
   11: 0x47e080a1 <the hole>
   12: 0x47e080a1 <the hole>
   13: 0x47e080a1 <the hole>
   14: 0x47e080a1 <the hole>
   15: 0x47e080a1 <the hole>
   16: 0x47e080a1 <the hole>
 }

Now to figure out why.