This reminds me of a trick Monotone VCS in C++ had to print out specific variables upon failure. Usually they'd do nothing, but upon hitting an invariant or sim

This reminds me of a trick Monotone VCS in C++ had to print out specific variables upon failure. Usually they'd do nothing, but upon hitting an invariant or similar it would dump all the listed ones out. A bit harder to do cheaply in a safe language like Rust I guess... MM(variabletodump); example https://github.com/graydon/monotone/blob/master/graph.cc#L495 https://github.com/graydon/monotone/blob/master/graph.cc#L49... docs https://github.com/graydon/monotone/blob/master/HACKING#L252 https://github.com/graydon/monotone/blob/master/HACKING#L252 The implementation was a bit hairy https://github.com/graydon/monotone/blob/master/sanity.hh#L469 https://github.com/graydon/monotone/blob/master/sanity.hh#L4...