nix/tests/functional/lang/eval-fail-duplicate-traces.nix

# Check that we only omit duplicate stack traces when there's a bunch of them.
# Here, there's only a couple duplicate entries, so we output them all.
let
  throwAfter = n:
    if n > 0
    then throwAfter (n - 1)
    else throw "Uh oh!";
in
  throwAfter 2
Fix segfault on infinite recursion in some cases This fixes a segfault on infinite function call recursion (rather than infinite thunk recursion) by tracking the function call depth in `EvalState`. Additionally, to avoid printing extremely long stack traces, stack frames are now deduplicated, with a `(19997 duplicate traces omitted)` message. This should only really be triggered in infinite recursion scenarios. Before: $ nix-instantiate --eval --expr '(x: x x) (x: x x)' Segmentation fault: 11 After: $ nix-instantiate --eval --expr '(x: x x) (x: x x)' error: stack overflow at «string»:1:14: 1\| (x: x x) (x: x x) \| ^ $ nix-instantiate --eval --expr '(x: x x) (x: x x)' --show-trace error: … from call site at «string»:1:1: 1\| (x: x x) (x: x x) \| ^ … while calling anonymous lambda at «string»:1:2: 1\| (x: x x) (x: x x) \| ^ … from call site at «string»:1:5: 1\| (x: x x) (x: x x) \| ^ … while calling anonymous lambda at «string»:1:11: 1\| (x: x x) (x: x x) \| ^ … from call site at «string»:1:14: 1\| (x: x x) (x: x x) \| ^ (19997 duplicate traces omitted) error: stack overflow at «string»:1:14: 1\| (x: x x) (x: x x) \| ^ 2023-12-15 19:52:21 +00:00			`# Check that we only omit duplicate stack traces when there's a bunch of them.`
			`# Here, there's only a couple duplicate entries, so we output them all.`
			`let`
			`throwAfter = n:`
			`if n > 0`
			`then throwAfter (n - 1)`
			`else throw "Uh oh!";`
			`in`
			`throwAfter 2`