MacOS/GLMakie: NSException when displaying GLMakie figure

[asinghvi17]

• what version of Makie are you running? (]st -m Makie) master
• can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie)
• What platform + GPU are you on? Mac M1

I randomly get uncaught SIGABRTs when displaying figures on Mac M1 with GLMakie:

julia> using GLMakie

julia> fig = Figure()
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSWindow should only be instantiated on the main thread!'
*** First throw call stack:
(
)
libc++abi: terminating due to uncaught exception of type NSException

[45503] signal 6: Abort trap: 6
in expression starting at none:0
__pthread_kill at /usr/lib/system/libsystem_kernel.dylib (unknown line)
Allocations: 14353417 (Pool: 14352381; Big: 1036); GC: 17

That's at the start of the session, no code run before it. It's also sporadic - no guarantee if I will hit it or not.

[asinghvi17]

Hmm, this might be a thread juggling issue? I can reliably replicate this with:

using GLMakie
_task = Threads.@spawn begin
       display(Figure())
end
fetch(task)

so if the executing thread is not the "main" thread according to macOS, this might fail...