Crash with stack overflow

[hfiguiere]

This is reproduced with this repository / crate:

https://gitlab.freedesktop.org/libopenraw/libopenraw.git

(I'm the developer for that crate)

cargo-depgraph 1.6.0

$ cargo depgraph --all-deps
thread 'main' has overflowed its stack
fatal runtime error: stack overflow
zsh: IOT instruction (core dumped)  cargo depgraph --all-deps

In gdb

Program received signal SIGSEGV, Segmentation fault.
0x000055555557c6c9 in cargo_depgraph::graph::update_node ()
(gdb) where
#0  0x000055555557c6c9 in cargo_depgraph::graph::update_node ()
#1  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#2  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#3  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#4  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#5  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#6  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#7  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#8  0x000055555557c833 in cargo_depgraph::graph::update_node ()
#9  0x000055555557c833 in cargo_depgraph::graph::update_node ()

[jplatte]

Hey! I don't think I'll get to debugging this anytime soon, but a PR to fix it would be appreciated if you (or somebody else) can figure out what's going wrong there.